Портал:Подводное плавание

Портал Википедии с контентом, связанным с подводным дайвингом.

Темы портала

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Технологии

Случайный портал

Подводное плавание

Зона входа и выхода на берег на Шарк-Элли, Миллерс-Пойнт, Южная Африка.

Определение темы

Подводное плавание можно охарактеризовать как все следующее:

• Деятельность человека – намеренная, целенаправленная, сознательная и субъективно осмысленная последовательность действий. Подводное дайвинг практикуется как часть профессии или для отдыха, когда практикующий погружается под поверхность воды или другой жидкости на период, который может варьироваться от секунд до порядка суток, либо подвергаясь воздействию окружающей среды. давления или изолироваться с помощью костюма, устойчивого к давлению, для взаимодействия с подводной средой для удовольствия, соревнований или в качестве средства достижения рабочего места с целью получения прибыли или в поисках знаний, и может вообще не использовать никакого оборудования или использовать широкую ряд оборудования, которое может включать дыхательные аппараты, защитную одежду, средства зрения, связи, движения, маневренности, плавучести и безопасности, а также инструменты для выполнения поставленной задачи.

Область действия портала

В сферу деятельности этого портала входят технологии, обеспечивающие водолазную деятельность, физиологические и медицинские аспекты дайвинга, навыки и процедуры дайвинга, а также обучение и регистрация дайверов, подводная деятельность, которая в некоторой степени зависит от дайвинга, экономическая, коммерческая, безопасная. и юридические аспекты дайвинга, биографические сведения об известных дайверах, изобретателях и производителях оборудования для дайвинга, а также об исследователях, занимающихся аспектами дайвинга.

Введение в подводное плавание

Водолазы с надводного снабжения едут по сцене к подводному рабочему месту

Подводное плавание , как вид деятельности человека, представляет собой практику спуска под поверхность воды для взаимодействия с окружающей средой. Его также часто называют дайвингом — неоднозначный термин, имеющий несколько возможных значений, в зависимости от контекста. Погружение в воду и воздействие высокого давления окружающей среды имеют физиологические эффекты, которые ограничивают глубину и продолжительность погружений под давлением окружающей среды . Люди физиологически и анатомически недостаточно приспособлены к условиям окружающей среды при дайвинге, поэтому было разработано различное оборудование, позволяющее увеличить глубину и продолжительность погружений человека и позволить выполнять различные виды работ.

При погружениях под давлением дайвер непосредственно подвергается воздействию давления окружающей воды. Дайвер под атмосферным давлением может погружаться с задержкой дыхания ( фридайвинг ) или использовать дыхательный аппарат для подводного плавания с аквалангом или погружения с поверхности , а техника погружения с насыщением снижает риск декомпрессионной болезни (DCS) после длительных глубоких погружений. Атмосферные водолазные костюмы (ADS) могут использоваться для изоляции дайвера от высокого давления окружающей среды. Погружные аппараты с экипажем могут расширить диапазон глубин, а дистанционно управляемые или роботизированные машины могут снизить риск для людей.

Окружающая среда подвергает дайвера широкому спектру опасностей, и хотя риски в значительной степени контролируются соответствующими навыками дайвинга , подготовкой , типами оборудования и дыхательными газами , используемыми в зависимости от режима, глубины и цели погружения, это занятие остается относительно опасным. . Профессиональный дайвинг обычно регулируется законодательством по охране труда и технике безопасности, тогда как любительский дайвинг может быть совершенно нерегулируемым. Дайвинг ограничен максимальной глубиной около 40 метров (130 футов) для любительского подводного плавания с аквалангом, 530 метров (1740 футов) для коммерческого погружения с насыщением и 610 метров (2000 футов) в атмосферных костюмах. Дайвинг также ограничивается условиями, которые не являются чрезмерно опасными, хотя приемлемый уровень риска может варьироваться, и могут произойти инциденты со смертельным исходом.

Рекреационный дайвинг (иногда называемый спортивным дайвингом или подводным плаванием) — популярный вид досуга. Технический дайвинг — это форма любительского дайвинга в более сложных условиях. Профессиональный дайвинг (коммерческий дайвинг, дайвинг в исследовательских целях или ради финансовой выгоды) предполагает работу под водой. Дайвинг в целях общественной безопасности — это подводная работа, выполняемая правоохранительными органами, пожарно-спасательными и подводными поисково-спасательными группами. Военный дайвинг включает в себя боевой дайвинг, очистной дайвинг и содержание кораблей .Глубоководное дайвинг — это подводное плавание, обычно с надводным оборудованием, которое часто подразумевает использованиестандартной водолазной одеждыс традиционным медным шлемом. Дайвинг в каске— это любая форма дайвинга сошлемом, включая стандартный медный шлем и другие видысо свободным потокомилегких шлемов. История ныряния с задержкой дыхания восходит, по крайней мере, к классическим временам, и есть свидетельства доисторическойохоты и сбораморепродуктов, которые, возможно, включали подводное плавание. Технические достижения, позволяющие подавать дайверу дыхательный газ под водой при атмосферном давлении, появились недавно, а автономные дыхательные системы стали развиваться ускоренными темпами после Второймировой войны. ( Полная статья... )

Как пользоваться этим порталом

• Есть несколько способов найти контент в Википедии.

  Если у вас есть полезная строка поиска, поиск в Google весьма эффективен.

  Поиск в Википедии приведет вас прямо к статье, если вы знаете точное название или если в Википедии есть перенаправление на статью. Он также предложит другие статьи в Википедии, которые могут соответствовать вашим критериям поиска.

  Поле навигации внизу страниц, имеющих отношение к проекту, содержит ссылки на перечисленные статьи. (В настоящее время недоступно на мобильных устройствах).

  Если вам нужен список статей проекта, который вы можете просматривать в поисках вдохновения или узнаваемого названия статьи, то есть несколько других путей:

  • Краткое описание подводного плавания представляет собой иерархический список всех статей, но он не всегда может быть актуальным.
  • Указатель подводного плавания представляет собой алфавитный список статей (также не всегда актуальный). Он имеет субиндексы для некоторых связанных групп статей, таких как:
    • Указатель мест для любительского дайвинга
    • Индекс подводных дайверов
  • Глоссарий терминологии подводного дайвинга представляет собой алфавитный список терминов, обычно используемых в дайвинге, и их значений в этом контексте. Полезный краткий справочник. Определение часто содержит ссылку на подробную основную статью или раздел статьи, посвященный этому термину. Если вы не можете найти термин и достаточно уверены, что это общеупотребительный термин для дайвинга на английском языке, оставьте заметку на странице обсуждения.

  Категория:Подводное плавание и связанные с ней подкатегории также должны содержать список всех статей, возможно, в иерархической структуре, отличной от той, которая используется для навигационного окна и списка структуры. Иногда система категорий может быть более подходящей для поиска информации. Это также полезно для обслуживания Википедии и отслеживания связности статей.

  Если у вас неограниченное время и нет особой цели, вы можете спуститься в кроличью нору — прочитайте основную статью темы « Подводное плавание» и щелкните любую ссылку, которая покажется интересной. Читайте, пока не найдете другую интересную ссылку, и нажмите на нее, в противном случае щелкните стрелку браузера, чтобы вернуться назад, и продолжайте. Остановитесь, когда реальность вторгается в вас, или вам становится скучно, вы устали, хотите пить или вспыхивает пожар.

  Ни одна из этих систем не является идеальной или полной. Если вы обнаружите ошибку или упущение, сообщите нам об этом или исправьте ее, если знаете как. Это краудсорсинговый проект – вы можете быть одним из толпы.

Обновить, добавив новые элементы ниже (очистить)

Режимы погружения

Указатель режимов погружения

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  Атмосферный водолазный костюм

  
  Атмосферный водолазный костюм ( ADS ) представляет собой небольшой шарнирно-сочлененный подводный аппарат для одного человека , напоминающий доспехи , со сложными герметичными соединениями, обеспечивающими шарнирное соединение при поддержании внутреннего давления в одну атмосферу. ADS может обеспечить погружение на глубину до 700 метров (2300 футов) в течение многих часов, устраняя большинство серьезных физиологических опасностей, связанных с глубокими погружениями. Пассажиру ADS не требуется декомпрессия , и нет необходимости в специальных дыхательных газовых смесях, поэтому при правильном функционировании ADS существует небольшая опасность декомпрессионной болезни или азотного наркоза . ADS может позволить менее опытным пловцам совершать глубокие погружения, хотя и за счет ловкости.
  
  Используемые в настоящее время атмосферные водолазные костюмы включают Newtsuit , Exosuit, Hardsuit и WASP, все из которых представляют собой автономные жесткие костюмы со встроенными двигательными установками. Костюм Hardsuit изготовлен из литого алюминия ( кованый алюминий в версии, созданной для ВМС США для спасения подводных лодок); верхний корпус изготовлен из литого алюминия , а нижний купол - из обработанного алюминия. WASP имеет трубчатую конструкцию из стеклопластика (GRP). ( Полная статья... )
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  Saturation diver working on the USS Monitor wreck at 70 m (230 ft) depth.

  
  Saturation diving is diving for periods long enough to bring all tissues into equilibrium with the partial pressures of the inert components of the breathing gas used. It is a diving mode that reduces the number of decompressions divers working at great depths must undergo by only decompressing divers once at the end of the diving operation, which may last days to weeks, having them remain under pressure for the whole period. A diver breathing pressurized gas accumulates dissolved inert gas used in the breathing mixture to dilute the oxygen to a non-toxic level in the tissues, which can cause decompression sickness ("the bends") if permitted to come out of solution within the body tissues; hence, returning to the surface safely requires lengthy decompression so that the inert gases can be eliminated via the lungs. Once the dissolved gases in a diver's tissues reach the saturation point, however, decompression time does not increase with further exposure, as no more inert gas is accumulated.
  
  Saturation diving takes advantage of this by having divers remain in that saturated state. When not in the water, the divers live in a sealed environment which maintains their pressurised state; this can be an ambient pressure underwater habitat or a saturation system at the surface, with transfer to and from the pressurised living quarters to the equivalent depth underwater via a closed, pressurised diving bell. This may be maintained for up to several weeks, and divers are decompressed to surface pressure only once, at the end of their tour of duty. By limiting the number of decompressions in this way, and using a conservative decompression schedule the risk of decompression sickness is significantly reduced, and the total time spent decompressing is minimised. Saturation divers typically breathe a helium–oxygen mixture to prevent nitrogen narcosis, and limit work of breathing, but at shallow depths saturation diving has been done on nitrox mixtures.
  
  Most of the physiological and medical aspects of diving to the same depths are much the same in saturation and bell-bounce ambient pressure diving, or are less of a problem, but there are medical and psychological effects of living under saturation for extended periods.
  
  Saturation diving is a specialized form of diving; of the 3,300 commercial divers employed in the United States in 2015, 336 were saturation divers. Special training and certification is required, as the activity is inherently hazardous, and a set of standard operating procedures, emergency procedures, and a range of specialised equipment is used to control the risk, that require consistently correct performance by all the members of an extended diving team. The combination of relatively large skilled personnel requirements, complex engineering, and bulky, heavy equipment required to support a saturation diving project make it an expensive diving mode, but it allows direct human intervention at places that would not otherwise be practical, and where it is applied, it is generally more economically viable than other options, if such exist. (Full article...)
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  Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California

  
  Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
  
  The copper helmeted free-flow standard diving dress is the version which made commercial diving a viable occupation, and although still used in some regions, this heavy equipment has been superseded by lighter free-flow helmets, and to a large extent, lightweight demand helmets, band masks and full-face diving masks. Breathing gases used include air, heliox, nitrox and trimix.
  
  Saturation diving is a mode of surface supplied diving in which the divers live under pressure in a saturation system or underwater habitat and are decompressed only at the end of a tour of duty.
  
  Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
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  A freediver on the ocean floor

  
  Freediving, free-diving, free diving, breath-hold diving, or skin diving, is a mode of underwater diving that relies on breath-holding until resurfacing rather than the use of breathing apparatus such as scuba gear.
  
  Besides the limits of breath-hold, immersion in water and exposure to high ambient pressure also have physiological effects that limit the depths and duration possible in freediving.
  
  Examples of freediving activities are traditional fishing techniques, competitive and non-competitive freediving, competitive and non-competitive spearfishing and freediving photography, synchronised swimming, underwater football, underwater rugby, underwater hockey, underwater target shooting and snorkeling. There are also a range of "competitive apnea" disciplines; in which competitors attempt to attain great depths, times, or distances on a single breath.
  
  Historically, the term free diving was also used to refer to scuba diving, due to the freedom of movement compared with surface supplied diving. (Full article...)
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  Surface-supplied divers riding a stage to the underwater workplace

  
  
  Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context.
  Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done.
  
  In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness (DCS) after long-duration deep dives. Atmospheric diving suits (ADS) may be used to isolate the diver from high ambient pressure. Crewed submersibles can extend depth range, and remotely controlled or robotic machines can reduce risk to humans.
  
  The environment exposes the diver to a wide range of hazards, and though the risks are largely controlled by appropriate diving skills, training, types of equipment and breathing gases used depending on the mode, depth and purpose of diving, it remains a relatively dangerous activity. Professional diving is usually regulated by occupational health and safety legislation, while recreational diving may be entirely unregulated.
  Diving activities are restricted to maximum depths of about 40 metres (130 ft) for recreational scuba diving, 530 metres (1,740 ft) for commercial saturation diving, and 610 metres (2,000 ft) wearing atmospheric suits. Diving is also restricted to conditions which are not excessively hazardous, though the level of risk acceptable can vary, and fatal incidents may occur.
  
  Recreational diving (sometimes called sport diving or subaquatics) is a popular leisure activity. Technical diving is a form of recreational diving under more challenging conditions. Professional diving (commercial diving, diving for research purposes, or for financial gain) involves working underwater. Public safety diving is the underwater work done by law enforcement, fire rescue, and underwater search and recovery dive teams. Military diving includes combat diving, clearance diving and ships husbandry.
  Deep sea diving is underwater diving, usually with surface-supplied equipment, and often refers to the use of standard diving dress with the traditional copper helmet. Hard hat diving is any form of diving with a helmet, including the standard copper helmet, and other forms of free-flow and lightweight demand helmets.
  The history of breath-hold diving goes back at least to classical times, and there is evidence of prehistoric hunting and gathering of seafoods that may have involved underwater swimming. Technical advances allowing the provision of breathing gas to a diver underwater at ambient pressure are recent, and self-contained breathing systems developed at an accelerated rate following the Second World War. (Full article...)
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  Recreational scuba diver

  
  Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The name scuba is an anacronym for "Self-Contained Underwater Breathing Apparatus" and was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, usually compressed air, affording them greater independence and movement than surface-supplied divers, and more time underwater than free divers. Although the use of compressed air is common, a gas blend with a higher oxygen content, known as enriched air or nitrox, has become popular due to the reduced nitrogen intake during long or repetitive dives. Also, breathing gas diluted with helium may be used to reduce the effects of nitrogen narcosis during deeper dives.
  
  Open-circuit scuba systems discharge the breathing gas into the environment as it is exhaled, and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver through a diving regulator. They may include additional cylinders for range extension, decompression gas or emergency breathing gas. Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases. The volume of gas used is reduced compared to that of open circuit, so a smaller cylinder or cylinders may be used for an equivalent dive duration. Rebreathers extend the time spent underwater compared to open circuit for the same metabolic gas consumption; they produce fewer bubbles and less noise than open circuit scuba, which makes them attractive to covert military divers to avoid detection, scientific divers to avoid disturbing marine animals, and media divers to avoid bubble interference.
  
  Scuba diving may be done recreationally or professionally in a number of applications, including scientific, military and public safety roles, but most commercial diving uses surface-supplied diving equipment when this is practicable. Scuba divers engaged in armed forces covert operations may be referred to as frogmen, combat divers or attack swimmers.
  
  A scuba diver primarily moves underwater by using fins attached to the feet, but external propulsion can be provided by a diver propulsion vehicle, or a sled pulled from the surface. Other equipment needed for scuba diving includes a mask to improve underwater vision, exposure protection by means of a diving suit, ballast weights to overcome excess buoyancy, equipment to control buoyancy, and equipment related to the specific circumstances and purpose of the dive, which may include a snorkel when swimming on the surface, a cutting tool to manage entanglement, lights, a dive computer to monitor decompression status, and signalling devices. Scuba divers are trained in the procedures and skills appropriate to their level of certification by diving instructors affiliated to the diver certification organisations which issue these certifications. These include standard operating procedures for using the equipment and dealing with the general hazards of the underwater environment, and emergency procedures for self-help and assistance of a similarly equipped diver experiencing problems. A minimum level of fitness and health is required by most training organisations, but a higher level of fitness may be appropriate for some applications. (Full article...)

Водолазное и вспомогательное оборудование

Указатель оборудования для дайвинга и вспомогательного оборудования

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  Один тип идентификационной этикетки баллона с найтроксом

  
  
  Найтрокс – это любая газовая смесь , состоящая (за исключением малых газов) из азота и кислорода . Сюда входит атмосферный воздух , который примерно на 78% состоит из азота, на 21% из кислорода и на 1% из других газов, в первую очередь аргона . В обычном применении, подводном дайвинге , найтрокс обычно отличается от воздуха и с ним обращаются по-другому. Наиболее распространенное использование смесей найтрокса, содержащих кислород в более высоких пропорциях, чем в атмосферном воздухе, - это подводное плавание с аквалангом , где пониженное парциальное давление азота полезно для уменьшения поглощения азота тканями организма , тем самым продлевая практическое время подводного погружения за счет снижениятребований к декомпрессии . или снижение риска декомпрессионной болезни (также известной как изгибы ).
  
  Найтрокс в меньшей степени используется при дайвинге с надводной подачей , поскольку эти преимущества сводятся к более сложным логистическим требованиям к найтроксу по сравнению с использованием простых компрессоров низкого давления для подачи дыхательного газа. Найтрокс также можно использовать при гипербарическом лечении декомпрессионной болезни , обычно при давлении, при котором чистый кислород может быть опасен. Найтрокс не во всех отношениях более безопасный газ, чем сжатый воздух; хотя его использование может снизить риск декомпрессионной болезни, оно увеличивает риск кислородного отравления и пожара.
  
  Хотя обычно это не называется найтроксом, обогащенная кислородом воздушная смесь обычно предоставляется при нормальном приземном давлении окружающей среды в качестве кислородной терапии пациентам с нарушениями дыхания и кровообращения. ( Полная статья... )
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  Israeli Navy Underwater Missions Unit transfers equipment using lifting-bags

  
  A lifting bag is an item of diving equipment consisting of a robust and air-tight bag with straps, which is used to lift heavy objects underwater by means of the bag's buoyancy. The heavy object can either be moved horizontally underwater by the diver or sent unaccompanied to the surface.
  
  Lift bag appropriate capacity should match the task at hand. If the lift bag is grossly oversized a runaway or otherwise out of control ascent may result. Commercially available lifting bags may incorporate dump valves to allow the operator to control the buoyancy during ascent, but this is a hazardous operation with high risk of entanglement in an uncontrolled lift or sinking. If a single bag is insufficient, multiple bags may be used, and should be distributed to suit the load.
  
  There are also lifting bags used on land as short lift jacks for lifting cars or heavy loads or lifting bags which are used in machines as a type of pneumatic actuator which provides load over a large area. These lifting bags of the AS/CR type are for example used in the brake mechanism of rollercoasters. (Full article...)
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  A liveaboard dive boat on the Similan Islands, Thailand

  
  A dive boat is a boat that recreational divers or professional scuba divers use to reach a dive site which they could not conveniently reach by swimming from the shore. Dive boats may be propelled by wind or muscle power, but are usually powered by internal combustion engines. Some features, like convenient access from the water, are common to all dive boats, while others depend on the specific application or region where they are used. The vessel may be extensively modified to make it fit for purpose, or may be used without much adaptation if it is already usable.
  
  Dive boats may simply transport divers and their equipment to and from the dive site for a single dive, or may provide longer term support and shelter for day trips or periods of several consecutive days. Deployment of divers may be while moored, at anchor, or under way, (also known as live-boating or live-boat diving). There are a range of specialised procedures for boat diving, which include water entry and exit, avoiding injury by the dive boat, and keeping the dive boat crew aware of the location of the divers in the water.
  
  There are also procedures used by the boat crew, to avoid injuring the divers in the water, keeping track of where they are during a dive, recalling the divers in an emergency, and ensuring that none are left behind. (Full article...)
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  Trimix scuba cylinder label

  
  A breathing gas is a mixture of gaseous chemical elements and compounds used for respiration. Air is the most common and only natural breathing gas, but other mixtures of gases, or pure oxygen, are also used in breathing equipment and enclosed habitats. Oxygen is the essential component for any breathing gas. Breathing gases for hyperbaric use have been developed to improve on the performance of ordinary air by reducing the risk of decompression sickness, reducing the duration of decompression, reducing nitrogen narcosis or allowing safer deep diving (Full article...)
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  Snorkeler wearing a clear silicone diving mask

  
  A diving mask (also half mask, dive mask or scuba mask) is an item of diving equipment that allows underwater divers, including scuba divers, free-divers, and snorkelers, to see clearly underwater. Surface supplied divers usually use a full face mask or diving helmet, but in some systems the half mask may be used. When the human eye is in direct contact with water as opposed to air, its normal environment, light entering the eye is refracted by a different angle and the eye is unable to focus the light on the retina. By providing an air space in front of the eyes, the eye is able to focus nearly normally. The shape of the air space in the mask slightly affects the ability to focus. Corrective lenses can be fitted to the inside surface of the viewport or contact lenses may be worn inside the mask to allow normal vision for people with focusing defects.
  
  When the diver descends, the ambient pressure rises, and it becomes necessary to equalise the pressure inside the mask with the external ambient pressure to avoid the barotrauma known as mask squeeze. This is done by allowing sufficient air to flow out through the nose into the mask to relieve the pressure difference, which requires the nose to be included in the airspace of the mask. Equalisation during ascent is automatic as excess air inside the mask easily leaks out past the seal.
  
  A wide range of viewport shapes and internal volumes are available, and each design will generally fit some shapes of face better than others. A good comfortable fit and a reliable seal around the edges of the rubber skirt is important to the correct function of the mask. National and international standards relating to diving masks provide a means of ensuring that they are manufactured to a suitable quality. (Full article...)
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  Diving cylinders to be filled at a diving air compressor station

  
  A diving cylinder or diving gas cylinder is a gas cylinder used to store and transport high pressure gas used in diving operations. This may be breathing gas used with a scuba set, in which case the cylinder may also be referred to as a scuba cylinder, scuba tank or diving tank. When used for an emergency gas supply for surface supplied diving or scuba, it may be referred to as a bailout cylinder or bailout bottle. It may also be used for surface-supplied diving or as decompression gas . A diving cylinder may also be used to supply inflation gas for a dry suit or buoyancy compensator. Cylinders provide gas to the diver through the demand valve of a diving regulator or the breathing loop of a diving rebreather.
  
  Diving cylinders are usually manufactured from aluminium or steel alloys, and when used on a scuba set are normally fitted with one of two common types of cylinder valve for filling and connection to the regulator. Other accessories such as manifolds, cylinder bands, protective nets and boots and carrying handles may be provided. Various configurations of harness may be used by the diver to carry a cylinder or cylinders while diving, depending on the application. Cylinders used for scuba typically have an internal volume (known as water capacity) of between 3 and 18 litres (0.11 and 0.64 cu ft) and a maximum working pressure rating from 184 to 300 bars (2,670 to 4,350 psi). Cylinders are also available in smaller sizes, such as 0.5, 1.5 and 2 litres, however these are usually used for purposes such as inflation of surface marker buoys, dry suits and buoyancy compensators rather than breathing. Scuba divers may dive with a single cylinder, a pair of similar cylinders, or a main cylinder and a smaller "pony" cylinder, carried on the diver's back or clipped onto the harness at the side. Paired cylinders may be manifolded together or independent. In technical diving, more than two scuba cylinders may be needed.
  
  When pressurised, the gas is compressed up to several hundred times atmospheric pressure. The selection of an appropriate set of diving cylinders for a diving operation is based on the amount of gas required to safely complete the dive. Diving cylinders are most commonly filled with air, but because the main components of air can cause problems when breathed underwater at higher ambient pressure, divers may choose to breathe from cylinders filled with mixtures of gases other than air. Many jurisdictions have regulations that govern the filling, recording of contents, and labelling for diving cylinders. Periodic testing and inspection of diving cylinders is often obligatory to ensure the safety of operators of filling stations. Pressurised diving cylinders are considered dangerous goods for commercial transportation, and regional and international standards for colouring and labelling may also apply. (Full article...)
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  Line Arrow Marker

  
  In cave (and occasionally wreck) diving, line markers are used for orientation as a visual and tactile reference on a permanent guideline. Directional markers (commonly a notched acute isosceles triangle in basic outline), are also known as line arrows or Dorff arrows, and point the way to an exit. Line arrows may mark the location of a "jump" location in a cave when two are placed adjacent to each other. Two adjacent arrows facing away from each other, mark a point in the cave where the diver is equidistant from two exits. Arrow direction can be identified by feel in low visibility.
  
  Non-directional markers ("cookies") are purely personal markers that mark specific spots, or the direction of one's chosen exit at line intersections where there are options. Their shape does not provide a tactile indication of direction as this could cause confusion in low visibility. One important reason to be adequately trained before cave diving is that incorrect marking can confuse and fatally endanger not only oneself, but also other divers. (Full article...)
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  Filling a spare air bailout cylinder

  
  A bailout bottle (BoB) or, more formally, bailout cylinder is a scuba cylinder carried by an underwater diver for use as an emergency supply of breathing gas in the event of a primary gas supply failure. A bailout cylinder may be carried by a scuba diver in addition to the primary scuba set, or by a surface supplied diver using either free-flow or demand systems. The bailout gas is not intended for use during the dive except in an emergency, and would be considered a fully redundant breathing gas supply if used correctly. The term may refer to just the cylinder, or the bailout set or emergency gas supply (EGS), which is the cylinder with the gas delivery system attached. The bailout set or bailout system is the combination of the emergency gas cylinder with the gas delivery system to the diver, which includes a diving regulator with either a demand valve, a bailout block, or a Rebreather diving#Bailout valve#bailout valve (BOV).
  
  In solo diving, a buddy bottle is a bailout cylinder carried as a substitute for an emergency gas supply from a diving buddy.
  
  Rebreathers also have bailout systems, often including an open-circuit bailout bottle. (Full article...)
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  Surface supplied diver on diving stage

  
  There are several categories of decompression equipment used to help divers decompress, which is the process required to allow divers to return to the surface safely after spending time underwater at higher ambient pressures.
  
  Decompression obligation for a given dive profile must be calculated and monitored to ensure that the risk of decompression sickness is controlled. Some equipment is specifically for these functions, both during planning before the dive and during the dive. Other equipment is used to mark the underwater position of the diver, as a position reference in low visibility or currents, or to assist the diver's ascent and control the depth.
  
  Decompression may be shortened ("accelerated") by breathing an oxygen-rich "decompression gas" such as a nitrox blend or pure oxygen. The high partial pressure of oxygen in such decompression mixes produces the effect known as the oxygen window. This decompression gas is often carried by scuba divers in side-slung cylinders. Cave divers who can only return by a single route, can leave decompression gas cylinders attached to the guideline ("stage" or "drop cylinders") at the points where they will be used. Surface-supplied divers will have the composition of the breathing gas controlled at the gas panel.
  
  Divers with long decompression obligations may be decompressed inside gas filled hyperbaric chambers in the water or at the surface, and in the extreme case, saturation divers are only decompressed at the end of a project, contract, or tour of duty that may be several weeks long. (Full article...)
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  Trimix scuba cylinder label

  
  Trimix is a breathing gas consisting of oxygen, helium and nitrogen and is used in deep commercial diving, during the deep phase of dives carried out using technical diving techniques, and in advanced recreational diving.
  
  The helium is included as a substitute for some of the nitrogen, to reduce the narcotic effect of the breathing gas at depth. With a mixture of three gases it is possible to create mixes suitable for different depths or purposes by adjusting the proportions of each gas. Oxygen content can be optimised for the depth to limit the risk of toxicity, and the inert component balanced between nitrogen (which is cheap but narcotic) and helium (which is not narcotic and reduces work of breathing, but is more expensive and increases heat loss).
  
  The mixture of helium and oxygen with a 0% nitrogen content is generally known as heliox. This is frequently used as a breathing gas in deep commercial diving operations, where it is often recycled to save the expensive helium component. Analysis of two-component gases is much simpler than three-component gases. (Full article...)
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  Diving regulator: The most familiar type is the single-hose open circuit scuba regulator, with first and second stages, low pressure inflator hose and submersible pressure gauge

  
  A diving regulator is a pressure regulator that controls the pressure of breathing gas for diving. The most commonly recognised application is to reduce pressurized breathing gas to ambient pressure and deliver it to the diver, but there are also other types of gas pressure regulator used for diving applications. The gas may be air or one of a variety of specially blended breathing gases. The gas may be supplied from a scuba cylinder carried by the diver, in which case it is called a scuba regulator, or via a hose from a compressor or high-pressure storage cylinders at the surface in surface-supplied diving. A gas pressure regulator has one or more valves in series which reduce pressure from the source, and use the downstream pressure as feedback to control the delivered pressure, or the upstream pressure as feedback to prevent excessive flow rates, lowering the pressure at each stage.
  
  The terms "regulator" and "demand valve" (DV) are often used interchangeably, but a demand valve is the final stage pressure-reduction regulator that delivers gas only while the diver is inhaling and reduces the gas pressure to approximately ambient. In single-hose demand regulators, the demand valve is either held in the diver's mouth by a mouthpiece or attached to the full-face mask or helmet. In twin-hose regulators the demand valve is included in the body of the regulator which is usually attached directly to the cylinder valve or manifold outlet, with a remote mouthpiece supplied at ambient pressure.
  
  A pressure-reduction regulator is used to control the delivery pressure of the gas supplied to a free-flow helmet or full-face mask, in which the flow is continuous, to maintain the downstream pressure which is limited by the ambient pressure of the exhaust and the flow resistance of the delivery system (mainly the umbilical and exhaust valve) and not much influenced by the breathing of the diver. Diving rebreather systems may also use regulators to control the flow of fresh gas, and demand valves, known as automatic diluent valves, to maintain the volume in the breathing loop during descent. Gas reclaim systems and built-in breathing systems (BIBS) use a different kind of regulator to control the flow of exhaled gas to the return hose and through the topside reclaim system, these are of the back-pressure regulator class.
  
  The performance of a regulator is measured by the cracking pressure and added mechanical work of breathing, and the capacity to deliver breathing gas at peak inspiratory flow rate at high ambient pressures without excessive pressure drop, and without excessive dead space. For some cold water diving applications the capacity to deliver high flow rates at low ambient temperatures without jamming due to regulator freezing is important. (Full article...)
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  Offshore support vessel Toisa Perseus with, in the background, the fifth-generation deepwater drillship Discoverer Enterprise, over the Thunder Horse Oil Field. Both are equipped with DP systems.

  
  
  Dynamic positioning (DP) is a computer-controlled system to automatically maintain a vessel's position and heading by using its own propellers and thrusters. Position reference sensors, combined with wind sensors, motion sensors and gyrocompasses, provide information to the computer pertaining to the vessel's position and the magnitude and direction of environmental forces affecting its position. Examples of vessel types that employ DP include ships and semi-submersible mobile offshore drilling units (MODU), oceanographic research vessels, cable layer ships and cruise ships.
  
  The computer program contains a mathematical model of the vessel that includes information pertaining to the wind and current drag of the vessel and the location of the thrusters. This knowledge, combined with the sensor information, allows the computer to calculate the required steering angle and thruster output for each thruster. This allows operations at sea where mooring or anchoring is not feasible due to deep water, congestion on the sea bottom (pipelines, templates) or other problems.
  
  Dynamic positioning may either be absolute in that the position is locked to a fixed point over the bottom, or relative to a moving object like another ship or an underwater vehicle. One may also position the ship at a favorable angle towards wind, waves and current, called weathervaning.
  
  Dynamic positioning is used by much of the offshore oil industry, for example in the North Sea, Persian Gulf, Gulf of Mexico, West Africa, and off the coast of Brazil. There are currently more than 1800 DP ships. (Full article...)
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  Conventional scuba weight-belt with quick-release buckle

  
  A diving weighting system is ballast weight added to a diver or diving equipment to counteract excess buoyancy. They may be used by divers or on equipment such as diving bells, submersibles or camera housings.
  
  Divers wear diver weighting systems, weight belts or weights to counteract the buoyancy of other diving equipment, such as diving suits and aluminium diving cylinders, and buoyancy of the diver. The scuba diver must be weighted sufficiently to be slightly negatively buoyant at the end of the dive when most of the breathing gas has been used, and needs to maintain neutral buoyancy at safety or obligatory decompression stops. During the dive, buoyancy is controlled by adjusting the volume of air in the buoyancy compensation device (BCD) and, if worn, the dry suit, in order to achieve negative, neutral, or positive buoyancy as needed. The amount of weight required is determined by the maximum overall positive buoyancy of the fully equipped but unweighted diver anticipated during the dive, with an empty buoyancy compensator and normally inflated dry suit. This depends on the diver's mass and body composition, buoyancy of other diving gear worn (especially the diving suit), water salinity, weight of breathing gas consumed, and water temperature. It normally is in the range of 2 kilograms (4.4 lb) to 15 kilograms (33 lb). The weights can be distributed to trim the diver to suit the purpose of the dive.
  
  Surface-supplied divers may be more heavily weighted to facilitate underwater work, and may be unable to achieve neutral buoyancy, and rely on the diving stage, bell, umbilical, lifeline, shotline or jackstay for returning to the surface.
  
  Free divers may also use weights to counteract buoyancy of a wetsuit. However, they are more likely to weight for neutral buoyancy at a specific depth, and their weighting must take into account not only the compression of the suit with depth, but also the compression of the air in their lungs, and the consequent loss of buoyancy. As they have no decompression obligation, they do not have to be neutrally buoyant near the surface at the end of a dive.
  
  If the weights have a method of quick release, they can provide a useful rescue mechanism: they can be dropped in an emergency to provide an instant increase in buoyancy which should return the diver to the surface. Dropping weights increases the risk of barotrauma and decompression sickness due to the possibility of an uncontrollable ascent to the surface. This risk can only be justified when the emergency is life-threatening or the risk of decompression sickness is small, as is the case in free diving and scuba diving when the dive is well short of the no-decompression limit for the depth. Often divers take great care to ensure the weights are not dropped accidentally, and heavily weighted divers may arrange their weights so subsets of the total weight can be dropped individually, allowing for a somewhat more controlled emergency ascent.
  
  The weights are generally made of lead because of its high density, reasonably low cost, ease of casting into suitable shapes, and resistance to corrosion. The lead can be cast in blocks, cast shapes with slots for straps, or shaped as pellets known as "shot" and carried in bags. There is some concern that lead diving weights may constitute a toxic hazard to users and environment, but little evidence of significant risk. (Full article...)
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  Two divers, one wearing a 1 atmosphere diving suit and the other standard diving dress, preparing to explore the wreck of the RMS Lusitania, 1935

  
  A diving suit is a garment or device designed to protect a diver from the underwater environment. A diving suit may also incorporate a breathing gas supply (such as for a standard diving dress or atmospheric diving suit), but in most cases the term applies only to the environmental protective covering worn by the diver. The breathing gas supply is usually referred to separately. There is no generic term for the combination of suit and breathing apparatus alone. It is generally referred to as diving equipment or dive gear along with any other equipment necessary for the dive.
  
  Diving suits can be divided into two classes: "soft" or ambient pressure diving suits – examples are wetsuits, dry suits, semi-dry suits and dive skins – and "hard" or atmospheric pressure diving suits, armored suits that keep the diver at atmospheric pressure at any depth within the operating range of the suit. (Full article...)
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  Surface supplied commercial diving equipment on display at a trade show

  
  Diving equipment is equipment used by underwater divers to make diving activities possible, easier, safer and/or more comfortable. This may be equipment primarily intended for this purpose, or equipment intended for other purposes which is found to be suitable for diving use.
  
  The fundamental item of diving equipment used by divers other than freedivers, is underwater breathing apparatus, such as scuba equipment, and surface-supplied diving equipment, but there are other important items of equipment that make diving safer, more convenient or more efficient. Diving equipment used by recreational scuba divers, also known as scuba gear, is mostly personal equipment carried by the diver, but professional divers, particularly when operating in the surface supplied or saturation mode, use a large amount of support equipment not carried by the diver.
  
  Equipment which is used for underwater work or other activities which is not directly related to the activity of diving, or which has not been designed or modified specifically for underwater use by divers is not considered to be diving equipment. (Full article...)

Дайвинг-процедуры

Указатель процедур дайвинга

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  Команда дайверов слушает инструктаж по технике безопасности от своего супервайзера по дайвингу.

  
  Супервайзер по дайвингу - это профессиональный член команды водолазов , который несет прямую ответственность за безопасность водолазных операций и управление любыми инцидентами или несчастными случаями, которые могут произойти во время операции; Супервайзер должен находиться на контрольной точке водолазной операции на протяжении всего водолазного действия, а также управлять запланированным погружением и любыми непредвиденными обстоятельствами, которые могут возникнуть. Детали компетенции, требований, квалификации, регистрации и официального назначения различаются в зависимости от юрисдикции и соответствующих кодексов практики. Супервайзеры по дайвингу используются в коммерческом дайвинге , военном дайвинге , дайвинге в целях общественной безопасности и научных водолазных операциях.
  
  Контрольная точка — это место, где супервайзер может лучше всего контролировать состояние дайвера и ход погружения. При подводном плавании это обычно происходит на палубе дайв-бота, где есть хороший обзор поверхности над рабочей зоной, или на берегу в близлежащей точке, где дайверов можно увидеть, когда они всплывают на поверхность. Для погружений с поверхности вид на воду обычно по-прежнему необходим, а также требуется вид на линейные тендеры, обслуживающие шлангокабели, если только нет прямой видеотрансляции от дайверов и двусторонней аудиосвязи с тендерами. Позиция управления также включает газовую панель и панель связи, поэтому руководитель может оставаться в максимально полной информации о состоянии дайверов и их систем жизнеобеспечения во время погружения. Для погружений с колоколом и погружений с насыщением ситуация более сложная, и пост управления вполне может находиться внутри отсека, где установлена ​​аппаратура связи, управления и контроля колокола и систем жизнеобеспечения.
  
  В рекреационном дайвинге этот термин используется для обозначения лиц, управляющих рекреационным погружением, имеющих такие сертификаты, как дайвмастер ,
  специалист по контролю дайвинга, координатор дайвинга и т. д. ( Полная статья... )
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  Dive profile of an actual dive as recorded by a personal dive computer and displayed on a desktop screen using dive logging software. In this case depth is in metres.

  
  A dive profile is a description of a diver's pressure exposure over time. It may be as simple as just a depth and time pair, as in: "sixty for twenty," (a bottom time of 20 minutes at a depth of 60 feet) or as complex as a second by second graphical representation of depth and time recorded by a personal dive computer. Several common types of dive profile are specifically named, and these may be characteristic of the purpose of the dive. For example, a working dive at a limited location will often follow a constant depth (square) profile, and a recreational dive is likely to follow a multilevel profile, as the divers start deep and work their way up a reef to get the most out of the available breathing gas. The names are usually descriptive of the graphic appearance.
  
  The intended dive profile is useful as a planning tool as an indication of the risks of decompression sickness and oxygen toxicity for the exposure, to calculate a decompression schedule for the dive, and also for estimating the volume of open-circuit breathing gas needed for a planned dive, as these depend in part upon the depth and duration of the dive. A dive profile diagram is conventionally drawn with elapsed time running from left to right and depth increasing down the page.
  
  Many personal dive computers record the instantaneous depth at small time increments during the dive. This data can sometimes be displayed directly on the dive computer or more often downloaded to a personal computer, tablet, or smartphone and displayed in graphic form as a dive profile. (Full article...)
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  The hand signal "OK"

  
  Diver communications are the methods used by divers to communicate with each other or with surface members of the dive team. In professional diving, diver communication is usually between a single working diver and the diving supervisor at the surface control point. This is considered important both for managing the diving work, and as a safety measure for monitoring the condition of the diver. The traditional method of communication was by line signals, but this has been superseded by voice communication, and line signals are now used in emergencies when voice communications have failed. Surface supplied divers often carry a closed circuit video camera on the helmet which allows the surface team to see what the diver is doing and to be involved in inspection tasks. This can also be used to transmit hand signals to the surface if voice communications fails. Underwater slates may be used to write text messages which can be shown to other divers, and there are some dive computers which allow a limited number of pre-programmed text messages to be sent through-water to other divers or surface personnel with compatible equipment.
  
  Communication between divers and between surface personnel and divers is imperfect at best, and non-existent at worst, as a consequence of the physical characteristics of water. This prevents divers from performing at their full potential. Voice communication is the most generally useful format underwater, as visual forms are more affected by visibility, and written communication and signing are relatively slow and restricted by diving equipment.
  
  Recreational divers do not usually have access to voice communication equipment, and it does not generally work with a standard scuba demand valve mouthpiece, so they use other signals. Hand signals are generally used when visibility allows, and there are a range of commonly used signals, with some variations. These signals are often also used by professional divers to communicate with other divers. There is also a range of other special purpose non-verbal signals, mostly used for safety and emergency communications. (Full article...)
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  Ice diving is a type of penetration diving where the dive takes place under ice. Because diving under ice places the diver in an overhead environment typically with only a single entry/exit point, it requires special procedures and equipment. Ice diving is done for purposes of recreation, scientific research, public safety (usually search and rescue/recovery) and other professional or commercial reasons.
  
  The most obvious hazards of ice diving are getting lost under the ice, hypothermia, and regulator failure due to freezing. Scuba divers are generally tethered for safety. This means that the diver wears a harness to which a line is secured, and the other end of the line is secured above the surface and monitored by an attendant. Surface supplied equipment inherently provides a tether, and reduces the risks of regulator first stage freezing as the first stage can be managed by the surface team, and the breathing gas supply is less limited. For the surface support team, the hazards include freezing temperatures and falling through thin ice. (Full article...)
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  SCUBA Diver in the mountain lake Lai da Marmorera 1,680 metres (5,510 ft) above sea level)

  
  
  Altitude diving is underwater diving using scuba or surface supplied diving equipment where the surface is 300 metres (980 ft) or more above sea level (for example, a mountain lake). Altitude is significant in diving because it affects the decompression requirement for a dive, so that the stop depths and decompression times used for dives at altitude are different from those used for the same dive profile at sea level. The U.S. Navy tables recommend that no alteration be made for dives at altitudes lower than 91 metres (299 ft) and for dives between 91 and 300 meters correction is required for dives deeper than 44 metres (144 ft) of sea water. Most recently manufactured decompression computers can automatically compensate for altitude. (Full article...)
• Image 6

  

  Recreational scuba diver

  
  Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The name scuba is an anacronym for "Self-Contained Underwater Breathing Apparatus" and was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, usually compressed air, affording them greater independence and movement than surface-supplied divers, and more time underwater than free divers. Although the use of compressed air is common, a gas blend with a higher oxygen content, known as enriched air or nitrox, has become popular due to the reduced nitrogen intake during long or repetitive dives. Also, breathing gas diluted with helium may be used to reduce the effects of nitrogen narcosis during deeper dives.
  
  Open-circuit scuba systems discharge the breathing gas into the environment as it is exhaled, and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver through a diving regulator. They may include additional cylinders for range extension, decompression gas or emergency breathing gas. Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases. The volume of gas used is reduced compared to that of open circuit, so a smaller cylinder or cylinders may be used for an equivalent dive duration. Rebreathers extend the time spent underwater compared to open circuit for the same metabolic gas consumption; they produce fewer bubbles and less noise than open circuit scuba, which makes them attractive to covert military divers to avoid detection, scientific divers to avoid disturbing marine animals, and media divers to avoid bubble interference.
  
  Scuba diving may be done recreationally or professionally in a number of applications, including scientific, military and public safety roles, but most commercial diving uses surface-supplied diving equipment when this is practicable. Scuba divers engaged in armed forces covert operations may be referred to as frogmen, combat divers or attack swimmers.
  
  A scuba diver primarily moves underwater by using fins attached to the feet, but external propulsion can be provided by a diver propulsion vehicle, or a sled pulled from the surface. Other equipment needed for scuba diving includes a mask to improve underwater vision, exposure protection by means of a diving suit, ballast weights to overcome excess buoyancy, equipment to control buoyancy, and equipment related to the specific circumstances and purpose of the dive, which may include a snorkel when swimming on the surface, a cutting tool to manage entanglement, lights, a dive computer to monitor decompression status, and signalling devices. Scuba divers are trained in the procedures and skills appropriate to their level of certification by diving instructors affiliated to the diver certification organisations which issue these certifications. These include standard operating procedures for using the equipment and dealing with the general hazards of the underwater environment, and emergency procedures for self-help and assistance of a similarly equipped diver experiencing problems. A minimum level of fitness and health is required by most training organisations, but a higher level of fitness may be appropriate for some applications. (Full article...)
• Image 7

  In-water recompression (IWR) or underwater oxygen treatment is the emergency treatment of decompression sickness (DCS) by returning the diver underwater to help the gas bubbles in the tissues, which are causing the symptoms, to resolve. It is a procedure that exposes the diver to significant risk which should be compared with the risk associated with the available options and balanced against the probable benefits. Some authorities recommend that it is only to be used when the time to travel to the nearest recompression chamber is too long to save the victim's life; others take a more pragmatic approach and accept that in some circumstances IWR is the best available option. The risks may not be justified for case of mild symptoms likely to resolve spontaneously, or for cases where the diver is likely to be unsafe in the water, but in-water recompression may be justified in cases where severe outcomes are likely if not recompressed, if conducted by a competent and suitably equipped team.
  
  Carrying out in-water recompression when there is a nearby recompression chamber or without suitable equipment and training is never a desirable option. The risk of the procedure is due to the diver suffering from DCS being seriously ill and may become paralysed, unconscious, or stop breathing while underwater. Any one of these events is likely to result in the diver drowning or asphyxiating or suffering further injury during a subsequent rescue to the surface. This risk can be reduced by improving airway security by using surface supplied gas and a helmet or full-face mask. Risk of injury during emergency surfacing is minimised by treatment on 100% oxygen, which is also the only gas with a reliable record of positive outcomes. Early recompression on oxygen has a high rate of complete resolution of symptoms, even for shallower and shorter treatment than the highly successful US Navy Treatment Table 6.
  
  Several schedules have been published for in-water recompression treatment, but little data on their efficacy is available. The Australian Navy tables and US Navy Tables may have the largest amount of empirical evidence supporting their efficacy. (Full article...)
• Image 8

  

  Diver Trevor Jackson returning from a 600 ft (183 m) dive

  
  Technical diving (also referred to as tec diving or tech diving) is scuba diving that exceeds the agency-specified limits of recreational diving for non-professional purposes. Technical diving may expose the diver to hazards beyond those normally associated with recreational diving, and to a greater risk of serious injury or death. The risk may be reduced by appropriate skills, knowledge and experience, and by using suitable equipment and procedures. The skills may be developed through appropriate specialised training and experience. The equipment involves breathing gases other than air or standard nitrox mixtures, and multiple gas sources.
  
  The popularisation of the term technical diving has been credited to Michael Menduno, who was editor of the (now defunct) diving magazine aquaCorps Journal, but the concept and term, technical diving, go back at least as far as 1977, and divers have been engaging in what is now commonly referred to as technical diving for decades. (Full article...)
• Image 9

  

  Solo diver surveying a dive site. The bailout cylinder can be seen slung at the diver's left side

  
  
  Solo diving is the practice of self-sufficient underwater diving without a "dive buddy", particularly with reference to scuba diving, but the term is also applied to freediving. Professionally, solo diving has always been an option which depends on operational requirements and risk assessment. Surface supplied diving and atmospheric suit diving are commonly single diver underwater activities but are accompanied by an on-surface support team dedicated to the safety of the diver, including a stand-by diver, and are not considered solo diving in this sense.
  
  Solo freediving has occurred for millennia as evidenced by artifacts dating back to the ancient people of Mesopotamia when people dived to gather food and to collect pearl oysters. It wasn't until the 1950s, with the development of formalised scuba diving training, that recreational solo diving was deemed to be dangerous, particularly for beginners. In an effort to mitigate associated risks, some scuba certification agencies incorporated the practice of buddy diving into their diver training programmes. The true risk of solo diving relative to buddy diving in the same environmental conditions has never been reliably established, and may have been significantly overstated by some organisations, though it is generally recognised that buddy and team diving, when performed as specified in the manuals, will enhance safety to some extent depending on circumstances.
  
  Some divers, typically those with advanced underwater skills, prefer solo diving over buddy diving and acknowledge responsibility for their own safety. One of the more controversial reasons given being the uncertain competence of arbitrarily allocated dive buddies imposed on divers by service providers protected from liability by waivers. Others simply prefer solitude while communing with nature, or find the burden of continuously monitoring another person reduces their enjoyment of the activity, or engage in activities which are incompatible with effective buddy diving practices, and accept the possibility of slightly increased risk, just as others accept the increased risk associated with deeper dives, planned decompression, or penetration under an overhead.
  
  The recreational solo diver uses enhanced procedures, skills and equipment to mitigate the risks associated with not having another competent diver immediately available to assist if something goes wrong. The skills and procedures may be learned through a variety of effective methods to achieve appropriate competence, including formal training programmes with associated assessment and certification. Recreational solo diving, once discouraged by most training agencies, has been accepted since the late 1990s by some agencies that will train and certify experienced divers skilled in self-sufficiency and the use of redundant backup scuba equipment. In most countries there is no legal impediment to solo recreational diving, with or without certification. (Full article...)
• Image 10

  

  Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California

  
  Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
  
  The copper helmeted free-flow standard diving dress is the version which made commercial diving a viable occupation, and although still used in some regions, this heavy equipment has been superseded by lighter free-flow helmets, and to a large extent, lightweight demand helmets, band masks and full-face diving masks. Breathing gases used include air, heliox, nitrox and trimix.
  
  Saturation diving is a mode of surface supplied diving in which the divers live under pressure in a saturation system or underwater habitat and are decompressed only at the end of a tour of duty.
  
  Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
• Image 11

  

  Beginner diver in St. Croix, United States Virgin Islands

  
  Recreational diving or sport diving is diving for the purpose of leisure and enjoyment, usually when using scuba equipment. The term "recreational diving" may also be used in contradistinction to "technical diving", a more demanding aspect of recreational diving which requires more training and experience to develop the competence to reliably manage more complex equipment in the more hazardous conditions associated with the disciplines. Breath-hold diving for recreation also fits into the broader scope of the term, but this article covers the commonly used meaning of scuba diving for recreational purposes, where the diver is not constrained from making a direct near-vertical ascent to the surface at any point during the dive, and risk is considered low.
  
  The equipment used for recreational diving is mostly open circuit scuba, though semi closed and fully automated electronic closed circuit rebreathers may be included in the scope of recreational diving. Risk is managed by training the diver in a range of standardised procedures and skills appropriate to the equipment the diver chooses to use and the environment in which the diver plans to dive. Further experience and development of skills by practice will improve the diver's ability to dive safely. Specialty training is made available by the recreational diver training industry and diving clubs to increase the range of environments and venues the diver can enjoy at an acceptable level of risk.
  
  Reasons to dive and preferred diving activities may vary during the personal development of a recreational diver, and may depend on their psychological profile and their level of dedication to the activity. Most divers average less than eight dives per year, but some total several thousand dives over a few decades and continue diving into their 60s and 70s, occasionally older. Recreational divers may frequent local dive sites or dive as tourists at more distant venues known for desirable underwater environments. An economically significant diving tourism industry services recreational divers, providing equipment, training and diving experiences, generally by specialist providers known as dive centers, dive schools, live-aboard, day charter and basic dive boats.
  
  Legal constraints on recreational diving vary considerably across jurisdictions. Recreational diving may be industry regulated or regulated by law to some extent. The legal responsibility for recreational diving service providers is usually limited as far as possible by waivers which they require the customer to sign before engaging in any diving activity. The extent of responsibility of recreational buddy divers is unclear, but buddy diving is generally recommended by recreational diver training agencies as safer than solo diving, and some service providers insist that customers dive in buddy pairs. The evidence supporting this policy is inconclusive. (Full article...)
• Image 12

  

  A Navy buddy diver team checking their gauges together

  
  
  Buddy diving is the use of the buddy system by scuba divers. It is a set of safety procedures intended to improve the chances of avoiding or surviving accidents in or under water by having divers dive in a group of two or sometimes three. When using the buddy system, members of the group dive together and co-operate with each other, so that they can help or rescue each other in the event of an emergency. This is most effective if both divers are competent in all relevant skills and sufficiently aware of the situation that they can respond in time, which is a matter of both attitude and competence.
  
  In recreational diving, a pair of divers is usually considered best for buddy diving. With threesomes, one diver can easily lose the attention of the other two, and groups of more than three divers are not using the buddy system. The system is likely to be effective in mitigating out-of-air emergencies, non-diving medical emergencies and entrapment in ropes or nets. When used with the buddy check it can help avoid the omission, misuse and failure of diving equipment.
  
  In technical diving activities such as cave diving, threesomes are considered an acceptable practice. This is usually referred to as team diving to distinguish it from buddy diving in pairs.
  
  When professional divers dive as buddy pairs their responsibility to each other is specified as part of standard operating procedures, code of practice or governing legislation. (Full article...)
• Image 13

  

  A shotline with decompression trapeze provides a relatively safe and convenient place for in-water decompression.

  
  
  Dive planning is the process of planning an underwater diving operation. The purpose of dive planning is to increase the probability that a dive will be completed safely and the goals achieved. Some form of planning is done for most underwater dives, but the complexity and detail considered may vary enormously.
  
  Professional diving operations are usually formally planned and the plan documented as a legal record that due diligence has been done for health and safety purposes. Recreational dive planning may be less formal, but for complex technical dives, can be as formal, detailed and extensive as most professional dive plans. A professional diving contractor will be constrained by the code of practice, standing orders or regulatory legislation covering a project or specific operations within a project, and is responsible for ensuring that the scope of work to be done is within the scope of the rules relevant to that work. A recreational (including technical) diver or dive group is generally less constrained, but nevertheless is almost always restricted by some legislation, and often also the rules of the organisations to which the divers are affiliated.
  
  The planning of a diving operation may be simple or complex. In some cases the processes may have to be repeated several times before a satisfactory plan is achieved, and even then the plan may have to be modified on site to suit changed circumstances. The final product of the planning process may be formally documented or, in the case of recreational divers, an agreement on how the dive will be conducted. A diving project may consist of a number of related diving operations.
  
  A documented dive plan may contain elements from the following list:

  • Overview of Diving Activities
  • Schedule of Diving Operations
  • Specific Dive Plan Information
  • Budget

  (Full article...)
• Image 14

  

  Saturation diver working on the USS Monitor wreck at 70 m (230 ft) depth.

  
  Saturation diving is diving for periods long enough to bring all tissues into equilibrium with the partial pressures of the inert components of the breathing gas used. It is a diving mode that reduces the number of decompressions divers working at great depths must undergo by only decompressing divers once at the end of the diving operation, which may last days to weeks, having them remain under pressure for the whole period. A diver breathing pressurized gas accumulates dissolved inert gas used in the breathing mixture to dilute the oxygen to a non-toxic level in the tissues, which can cause decompression sickness ("the bends") if permitted to come out of solution within the body tissues; hence, returning to the surface safely requires lengthy decompression so that the inert gases can be eliminated via the lungs. Once the dissolved gases in a diver's tissues reach the saturation point, however, decompression time does not increase with further exposure, as no more inert gas is accumulated.
  
  Saturation diving takes advantage of this by having divers remain in that saturated state. When not in the water, the divers live in a sealed environment which maintains their pressurised state; this can be an ambient pressure underwater habitat or a saturation system at the surface, with transfer to and from the pressurised living quarters to the equivalent depth underwater via a closed, pressurised diving bell. This may be maintained for up to several weeks, and divers are decompressed to surface pressure only once, at the end of their tour of duty. By limiting the number of decompressions in this way, and using a conservative decompression schedule the risk of decompression sickness is significantly reduced, and the total time spent decompressing is minimised. Saturation divers typically breathe a helium–oxygen mixture to prevent nitrogen narcosis, and limit work of breathing, but at shallow depths saturation diving has been done on nitrox mixtures.
  
  Most of the physiological and medical aspects of diving to the same depths are much the same in saturation and bell-bounce ambient pressure diving, or are less of a problem, but there are medical and psychological effects of living under saturation for extended periods.
  
  Saturation diving is a specialized form of diving; of the 3,300 commercial divers employed in the United States in 2015, 336 were saturation divers. Special training and certification is required, as the activity is inherently hazardous, and a set of standard operating procedures, emergency procedures, and a range of specialised equipment is used to control the risk, that require consistently correct performance by all the members of an extended diving team. The combination of relatively large skilled personnel requirements, complex engineering, and bulky, heavy equipment required to support a saturation diving project make it an expensive diving mode, but it allows direct human intervention at places that would not otherwise be practical, and where it is applied, it is generally more economically viable than other options, if such exist. (Full article...)
• Image 15

  Buddy breathing is a rescue technique used in scuba diving "out of gas" emergencies, when two divers share one demand valve, alternately breathing from it. Techniques have been developed for buddy breathing from both twin-hose and single hose regulators, but to a large extent it has been superseded by safer and more reliable techniques using additional equipment, such as the use of a bailout cylinder or breathing through a secondary demand valve on the rescuer's regulator.
  
  Running out of breathing gas most commonly happens as a result of poor gas management. It can also happen due to unforeseen exertion or breathing equipment failure. Equipment failure resulting in the loss of all gas could be caused by failure of a pressure retaining component such as an O-ring or hose in the regulator or, in cold conditions, a freezing of water in the regulator resulting in a free flow from the demand valve. (Full article...)

Наука дайвинга

Указатель науки подводного плавания

• Image 1

  

  Пример растворенного твердого вещества (слева)

  
  В химии растворимость — это способность вещества ( растворенного вещества ) образовывать раствор с другим веществом ( растворителем) . Нерастворимость – противоположное свойство, неспособность растворенного вещества образовывать такой раствор.
  
  Степень растворимости вещества в конкретном растворителе обычно измеряется как концентрация растворенного вещества в насыщенном растворе, в котором растворенное вещество больше не растворяется. Говорят, что в этот момент два вещества находятся в равновесии растворимости . Для некоторых растворенных веществ и растворителей такого предела может не быть, и в этом случае говорят, что эти два вещества « смешиваются во всех пропорциях» (или просто «смешиваются»).
  
  Растворенное вещество может быть твердым , жидким или газообразным , тогда как растворитель обычно бывает твердым или жидким. Оба могут быть чистыми веществами или сами быть растворами. Газы всегда смешиваются во всех пропорциях, за исключением очень крайних ситуаций, а твердое вещество или жидкость можно «растворить» в газе, только перейдя сначала в газообразное состояние.
  
  Растворимость главным образом зависит от состава растворенного вещества и растворителя (включая их pH и присутствие других растворенных веществ), а также от температуры и давления. Зависимость часто можно объяснить с точки зрения взаимодействия между частицами ( атомами , молекулами или ионами ) двух веществ, а также термодинамических понятий, таких как энтальпия и энтропия .
  
  При определенных условиях концентрация растворенного вещества может превышать обычный предел растворимости. В результате получается пересыщенный раствор , который является метастабильным и быстро исключает избыток растворенного вещества, если появляется подходящее место зародышеобразования .
  
  Понятие растворимости не применяется, когда между двумя веществами происходит необратимая химическая реакция , например реакция гидроксида кальция с соляной кислотой ; даже если неформально можно сказать, что одно «растворило» другое. Растворимость также отличается от скорости растворения , которая показывает, насколько быстро твердое растворенное вещество растворяется в жидком растворителе. Это свойство зависит от многих других переменных, таких как физическая форма двух веществ, а также способ и интенсивность смешивания.
  
  Понятие и мера растворимости чрезвычайно важны во многих науках, помимо химии, таких как геология , биология , физика и океанография , а также в технике , медицине , сельском хозяйстве и даже в нетехнических видах деятельности, таких как рисование , уборка , приготовление пищи . и пивоварение . Большинство химических реакций, представляющих научный, промышленный или практический интерес, происходят только после растворения реагентов в подходящем растворителе. Вода на сегодняшний день является наиболее распространенным таким растворителем.
  
  Термин «растворимый» иногда используется для материалов, которые могут образовывать коллоидные суспензии очень мелких твердых частиц в жидкости. Однако количественная растворимость таких веществ обычно не определена четко. ( Полная статья... )
• Image 2

  

  The atmospheric pressure is roughly equal to the sum of partial pressures of constituent gases – oxygen, nitrogen, argon, water vapor, carbon dioxide, etc.

  
  
  In a mixture of gases, each constituent gas has a partial pressure which is the notional pressure of that constituent gas as if it alone occupied the entire volume of the original mixture at the same temperature. The total pressure of an ideal gas mixture is the sum of the partial pressures of the gases in the mixture (Dalton's Law).
  
  The partial pressure of a gas is a measure of thermodynamic activity of the gas's molecules. Gases dissolve, diffuse, and react according to their partial pressures but not according to their concentrations in gas mixtures or liquids. This general property of gases is also true in chemical reactions of gases in biology. For example, the necessary amount of oxygen for human respiration, and the amount that is toxic, is set by the partial pressure of oxygen alone. This is true across a very wide range of different concentrations of oxygen present in various inhaled breathing gases or dissolved in blood; consequently, mixture ratios, like that of breathable 20% oxygen and 80% Nitrogen, are determined by volume instead of by weight or mass. Furthermore, the partial pressures of oxygen and carbon dioxide are important parameters in tests of arterial blood gases. That said, these pressures can also be measured in, for example, cerebrospinal fluid. (Full article...)
• Image 3

  

  Graph showing a tropical ocean thermocline (depth vs. temperature). Note the rapid change between 100 and 1000 meters. The temperature is nearly constant after 1500 meters depth.

  
  
  A thermocline (also known as the thermal layer or the metalimnion in lakes) is
  a distinct layer based on temperature within a large body of fluid (e.g. water, as in an ocean or lake; or air, e.g. an atmosphere) with a high gradient of distinct temperature differences associated with depth. In the ocean, the thermocline divides the upper mixed layer from the calm deep water below.
  
  Depending largely on season, latitude, and turbulent mixing by wind, thermoclines may be a semi-permanent feature of the body of water in which they occur, or they may form temporarily in response to phenomena such as the radiative heating/cooling of surface water during the day/night. Factors that affect the depth and thickness of a thermocline include seasonal weather variations, latitude, and local environmental conditions, such as tides and currents. (Full article...)
• Image 4

  

  Scuba diver decompressing at a planned stop during ascent from a dive

  
  
  Decompression theory is the study and modelling of the transfer of the inert gas component of breathing gases from the gas in the lungs to the tissues and back during exposure to variations in ambient pressure. In the case of underwater diving and compressed air work, this mostly involves ambient pressures greater than the local surface pressure, but astronauts, high altitude mountaineers, and travellers in aircraft which are not pressurised to sea level pressure, are generally exposed to ambient pressures less than standard sea level atmospheric pressure. In all cases, the symptoms caused by decompression occur during or within a relatively short period of hours, or occasionally days, after a significant pressure reduction.
  
  The term "decompression" derives from the reduction in ambient pressure experienced by the organism and refers to both the reduction in pressure and the process of allowing dissolved inert gases to be eliminated from the tissues during and after this reduction in pressure. The uptake of gas by the tissues is in the dissolved state, and elimination also requires the gas to be dissolved, however a sufficient reduction in ambient pressure may cause bubble formation in the tissues, which can lead to tissue damage and the symptoms known as decompression sickness, and also delays the elimination of the gas.
  
  Decompression modeling attempts to explain and predict the mechanism of gas elimination and bubble formation within the organism during and after changes in ambient pressure, and provides mathematical models which attempt to predict acceptably low risk and reasonably practicable procedures for decompression in the field. Both deterministic and probabilistic models have been used, and are still in use.
  
  Efficient decompression requires the diver to ascend fast enough to establish as high a decompression gradient, in as many tissues, as safely possible, without provoking the development of symptomatic bubbles. This is facilitated by the highest acceptably safe oxygen partial pressure in the breathing gas, and avoiding gas changes that could cause counterdiffusion bubble formation or growth. The development of schedules that are both safe and efficient has been complicated by the large number of variables and uncertainties, including personal variation in response under varying environmental conditions and workload. (Full article...)
• Image 5

  

  Diving reflex in a human baby

  
  The diving reflex, also known as the diving response and mammalian diving reflex, is a set of physiological responses to immersion that overrides the basic homeostatic reflexes, and is found in all air-breathing vertebrates studied to date. It optimizes respiration by preferentially distributing oxygen stores to the heart and brain, enabling submersion for an extended time.
  
  The diving reflex is exhibited strongly in aquatic mammals, such as seals, otters, dolphins, and muskrats, and exists as a lesser response in other animals, including human babies up to 6 months old (see infant swimming), and diving birds, such as ducks and penguins. Adult humans generally exhibit a mild response, the dive-hunting Sama-Bajau people being a notable outlier.
  
  The diving reflex is triggered specifically by chilling and wetting the nostrils and face while breath-holding, and is sustained via neural processing originating in the carotid chemoreceptors. The most noticeable effects are on the cardiovascular system, which displays peripheral vasoconstriction, slowed heart rate, redirection of blood to the vital organs to conserve oxygen, release of red blood cells stored in the spleen, and, in humans, heart rhythm irregularities. Although aquatic animals have evolved profound physiological adaptations to conserve oxygen during submersion, the apnea and its duration, bradycardia, vasoconstriction, and redistribution of cardiac output occur also in terrestrial animals as a neural response, but the effects are more profound in natural divers. (Full article...)
• Image 6

  

  Scuba diver decompressing at a planned stop during ascent from a dive

  
  The physiology of decompression is the aspect of physiology which is affected by exposure to large changes in ambient pressure, and involves a complex interaction of gas solubility, partial pressures and concentration gradients, diffusion, bulk transport and bubble mechanics in living tissues. Gas is breathed at ambient pressure, and some of this gas dissolves into the blood and other fluids. Inert gas continues to be taken up until the gas dissolved in the tissues is in a state of equilibrium with the gas in the lungs, (see: "Saturation diving"), or the ambient pressure is reduced until the inert gases dissolved in the tissues are at a higher concentration than the equilibrium state, and start diffusing out again.
  
  The absorption of gases in liquids depends on the solubility of the specific gas in the specific liquid, the concentration of gas, customarily expressed as partial pressure, and temperature. In the study of decompression theory the behaviour of gases dissolved in the body tissues is investigated and modeled for variations of pressure over time. Once dissolved, distribution of the dissolved gas is by perfusion, where the solvent (blood) is circulated around the diver's body, and by diffusion, where dissolved gas can spread to local regions of lower concentration when there is no bulk flow of the solvent. Given sufficient time at a specific partial pressure in the breathing gas, the concentration in the tissues will stabilise, or saturate, at a rate depending on the local solubility, diffusion rate and perfusion. If the concentration of the inert gas in the breathing gas is reduced below that of any of the tissues, there will be a tendency for gas to return from the tissues to the breathing gas. This is known as outgassing, and occurs during decompression, when the reduction in ambient pressure or a change of breathing gas reduces the partial pressure of the inert gas in the lungs.
  
  The combined concentrations of gases in any given tissue will depend on the history of pressure and gas composition. Under equilibrium conditions, the total concentration of dissolved gases will be less than the ambient pressure, as oxygen is metabolised in the tissues, and the carbon dioxide produced is much more soluble. However, during a reduction in ambient pressure, the rate of pressure reduction may exceed the rate at which gas can be eliminated by diffusion and perfusion, and if the concentration gets too high, it may reach a stage where bubble formation can occur in the supersaturated tissues. When the pressure of gases in a bubble exceed the combined external pressures of ambient pressure and the surface tension from the bubble - liquid interface, the bubbles will grow, and this growth can cause damage to tissues. Symptoms caused by this damage are known as decompression sickness.
  
  The actual rates of diffusion and perfusion, and the solubility of gases in specific tissues are not generally known, and vary considerably. However mathematical models have been proposed which approximate the real situation to a greater or lesser extent, and these decompression models are used to predict whether symptomatic bubble formation is likely to occur for a given pressure exposure profile. Efficient decompression requires the diver to ascend fast enough to establish as high a decompression gradient, in as many tissues, as safely possible, without provoking the development of symptomatic bubbles. This is facilitated by the highest acceptably safe oxygen partial pressure in the breathing gas, and avoiding gas changes that could cause counterdiffusion bubble formation or growth. The development of schedules that are both safe and efficient has been complicated by the large number of variables and uncertainties, including personal variation in response under varying environmental conditions and workload. (Full article...)
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  The physiology of underwater diving is the physiological adaptations to diving of air-breathing vertebrates that have returned to the ocean from terrestrial lineages. They are a diverse group that include sea snakes, sea turtles, the marine iguana, saltwater crocodiles, penguins, pinnipeds, cetaceans, sea otters, manatees and dugongs. All known diving vertebrates dive to feed, and the extent of the diving in terms of depth and duration are influenced by feeding strategies, but also, in some cases, with predator avoidance. Diving behaviour is inextricably linked with the physiological adaptations for diving and often the behaviour leads to an investigation of the physiology that makes the behaviour possible, so they are considered together where possible. Most diving vertebrates make relatively short shallow dives. Sea snakes, crocodiles, and marine iguanas only dive in inshore waters and seldom dive deeper than 10 meters (33 feet). Some of these groups can make much deeper and longer dives. Emperor penguins regularly dive to depths of 400 to 500 meters (1,300 to 1,600 feet) for 4 to 5 minutes, often dive for 8 to 12 minutes, and have a maximum endurance of about 22 minutes. Elephant seals stay at sea for between 2 and 8 months and dive continuously, spending 90% of their time underwater and averaging 20 minutes per dive with less than 3 minutes at the surface between dives. Their maximum dive duration is about 2 hours and they routinely feed at depths between 300 and 600 meters (980 and 1,970 feet), though they can exceed depths of 1,600 meters (5,200 feet). Beaked whales have been found to routinely dive to forage at depths between 835 and 1,070 meters (2,740 and 3,510 feet), and remain submerged for about 50 minutes. Their maximum recorded depth is 1,888 meters (6,194 feet), and the maximum duration is 85 minutes.
  
  Air-breathing marine vertebrates that dive to feed must deal with the effects of pressure at depth, hypoxia during apnea, and the need to find and capture their food. Adaptations to diving can be associated with these three requirements. Adaptations to pressure must deal with the mechanical effects of pressure on gas-filled cavities, solubility changes of gases under pressure, and possible direct effects of pressure on the metabolism, while adaptations to breath-hold capacity include modifications to metabolism, perfusion, carbon dioxide tolerance, and oxygen storage capacity. Adaptations to find and capture food vary depending on the food, but deep-diving generally involves operating in a dark environment.
  
  Diving vertebrates have increased the amount of oxygen stored in their internal tissues. This oxygen store has three components; oxygen contained in the air in the lungs, oxygen stored by haemoglobin in the blood, and by myoglobin, in muscle tissue, The muscle and blood of diving vertebrates have greater concentrations of haemoglobin and myoglobin than terrestrial animals. Myoglobin concentration in locomotor muscles of diving vertebrates is up to 30 times more than in terrestrial relatives. Haemoglobin is increased by both a relatively larger amount of blood and a larger proportion of red blood cells in the blood compared with terrestrial animals. The highest values are found in the mammals which dive deepest and longest.
  
  Body size is a factor in diving ability. A larger body mass correlates to a relatively lower metabolic rate, while oxygen storage is directly proportional to body mass, so larger animals should be able to dive for longer, all other things being equal. Swimming efficiency also affects diving ability, as low drag and high propulsive efficiency requires less energy for the same dive. Burst and glide locomotion is also often used to minimise energy consumption, and may involve using positive or negative buoyancy to power part of the ascent or descent.
  
  The responses seen in seals diving freely at sea are physiologically the same as those seen during forced dives in the laboratory. They are not specific to immersion in water, but are protective mechanisms against asphyxia which are common to all mammals but more effective and developed in seals. The extent to which these responses are expressed depends greatly on the seal's anticipation of dive duration.
  The regulation of bradycardia and vasoconstriction of the dive response in both mammals and diving ducks can be triggered by facial immersion, wetting of the nostrils and glottis, or stimulation of trigeminal and glossopharyngeal nerves.
  Animals cannot convert fats to glucose, and in many diving animals, carbohydrates are not readily available from the diet, nor stored in large quantities, so as they are essential for anaerobic metabolism, they could be a limiting factor.
  
  Decompression sickness (DCS) is a disease associated with metabolically inert gas uptake at pressure, and its subsequent release into the tissues in the form of bubbles. Marine mammals were thought to be relatively immune to DCS due to anatomical, physiological and behavioural adaptations that reduce tissue loading with dissolved nitrogen during dives, but observations show that gas bubbles may form, and tissue injury may occur under certain circumstances. Decompression modelelling using measured dive profiles predict the possibility of high blood and tissue nitrogen tensions. (Full article...)
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  A laboratory studying ambient pressure at Oregon State University

  
  The ambient pressure on an object is the pressure of the surrounding medium, such as a gas or liquid, in contact with the object. (Full article...)
• Image 9

  

  
  Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nutrient-rich upwelled water stimulates the growth and reproduction of primary producers such as phytoplankton. The biomass of phytoplankton and the presence of cool water in those regions allow upwelling zones to be identified by cool sea surface temperatures (SST) and high concentrations of chlorophyll a.
  
  The increased availability of nutrients in upwelling regions results in high levels of primary production and thus fishery production. Approximately 25% of the total global marine fish catches come from five upwellings, which occupy only 5% of the total ocean area. Upwellings that are driven by coastal currents or diverging open ocean have the greatest impact on nutrient-enriched waters and global fishery yields. (Full article...)
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  Scuba diver with bifocal lenses fitted to a mask

  
  
  Underwater vision is the ability to see objects underwater, and this is significantly affected by several factors. Underwater, objects are less visible because of lower levels of natural illumination caused by rapid attenuation of light with distance passed through the water. They are also blurred by scattering of light between the object and the viewer, also resulting in lower contrast. These effects vary with wavelength of the light, and color and turbidity of the water. The vertebrate eye is usually either optimised for underwater vision or air vision, as is the case in the human eye. The visual acuity of the air-optimised eye is severely adversely affected by the difference in refractive index between air and water when immersed in direct contact. Provision of an airspace between the cornea and the water can compensate, but has the side effect of scale and distance distortion. The diver learns to compensate for these distortions. Artificial illumination is effective to improve illumination at short range.
  
  Stereoscopic acuity, the ability to judge relative distances of different objects, is considerably reduced underwater, and this is affected by the field of vision. A narrow field of vision caused by a small viewport in a helmet results in greatly reduced stereoacuity, and associated loss of hand-eye coordination. At very short range in clear water distance is underestimated, in accordance with magnification due to refraction through the flat lens of the mask, but at greater distances - greater than arm's reach, the distance tends to be overestimated to a degree influenced by turbidity. Both relative and absolute depth perception are reduced underwater. Loss of contrast results in overestimation, and magnification effects account for underestimation at short range. Divers can to a large extent adapt to these effects over time and with practice.
  
  Light rays bend when they travel from one medium to another; the amount of bending is determined by the refractive indices of the two media. If one medium has a particular curved shape, it functions as a lens. The cornea, humours, and crystalline lens of the eye together form a lens that focuses images on the retina. The human eye is adapted for viewing in air. Water, however, has approximately the same refractive index as the cornea (both about 1.33), effectively eliminating the cornea's focusing properties. When immersed in water, instead of focusing images on the retina, they are focused behind the retina, resulting in an extremely blurred image from hypermetropia. This is largely avoided by having an air space between the water and the cornea, trapped inside the mask or helmet.
  
  Water attenuates light due to absorption and as light passes through water colour is selectively absorbed by the water. Color absorption is also affected by turbidity of the water and dissolved material. Water preferentially absorbs red light, and to a lesser extent, yellow, green and violet light, so the color that is least absorbed by water is blue light. Particulates and dissolved materials may absorb different frequencies, and this will affect the color at depth, with results such as the typically green color in many coastal waters, and the dark red-brown color of many freshwater rivers and lakes due to dissolved organic matter.
  
  Visibility is a term which generally predicts the ability of some human or instrument to optically detect an object in the given environment, and may be expressed as a measure of the distance at which an object or light can be discerned. Factors affecting visibility include illumination, length of the light path, particles which cause scattering, dissolved pigments which absorb specific colours, and salinity and temperature gradients which affect refractive index. Visibility can be measured in any arbitrary direction, and for various colour targets, but horizontal visibility of a black target reduces the variables and meets the requirements for a straight-forward and robust parameter for underwater visibility. Instruments are available for field estimates of visibility from the surface, which can inform the dive team on probable complications. (Full article...)
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  Signs explaining how to escape from a rip current, posted at Mission Beach, San Diego, California

  
  A rip current (also rip) is a specific type of water current that can occur near beaches where waves break. A rip is a strong, localized, and narrow current of water that moves directly away from the shore by cutting through the lines of breaking waves, like a river flowing out to sea. The force of the current in a rip is strongest and fastest next to the surface of the water.
  
  Rip currents can be hazardous to people in the water. Swimmers who are caught in a rip current and who do not understand what is happening, or who may not have the necessary water skills, may panic, or they may exhaust themselves by trying to swim directly against the flow of water. Because of these factors, rip currents are the leading cause of rescues by lifeguards at beaches. In the United States they cause an average of 71 deaths by drowning per year .
  
  A rip current is not the same thing as undertow, although some people use the term incorrectly when they are talking about a rip current. Contrary to popular belief, neither rip nor undertow can pull a person down and hold them under the water. A rip simply carries floating objects, including people, out to just beyond the zone of the breaking waves, at which point the current dissipates and releases everything it is carrying. (Full article...)
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  In physical chemistry, supersaturation occurs with a solution when the concentration of a solute exceeds the concentration specified by the value of solubility at equilibrium. Most commonly the term is applied to a solution of a solid in a liquid, but it can also be applied to liquids and gases dissolved in a liquid. A supersaturated solution is in a metastable state; it may return to equilibrium by separation of the excess of solute from the solution, by dilution of the solution by adding solvent, or by increasing the solubility of the solute in the solvent. (Full article...)
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  Turbidity standards of 5, 50, and 500 NTU

  
  Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of both water clarity and water quality.
  
  Fluids can contain suspended solid matter consisting of particles of many different sizes. While some suspended material will be large enough and heavy enough to settle rapidly to the bottom of the container if a liquid sample is left to stand (the settable solids), very small particles will settle only very slowly or not at all if the sample is regularly agitated or the particles are colloidal. These small solid particles cause the liquid to appear turbid.
  
  Turbidity (or haze) is also applied to transparent solids such as glass or plastic. In plastic production, haze is defined as the percentage of light that is deflected more than 2.5° from the incoming light direction. (Full article...)
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  Cold shock response is a series of neurogenic cardio-respiratory responses caused by sudden immersion in cold water.
  
  In cold water immersions, such as by falling through thin ice, cold shock response is perhaps the most common cause of death. Also, the abrupt contact with very cold water may cause involuntary inhalation, which, if underwater, can result in fatal drowning.
  
  Death which occurs in such scenarios is complex to investigate and there are several possible causes and phenomena that can take part. The cold water can cause heart attack due to severe vasoconstriction, where the heart has to work harder to pump the same volume of blood throughout the arteries. For people with pre-existing cardiovascular disease, the additional workload can result in myocardial infarction and/or acute heart failure, which ultimately may lead to a cardiac arrest. A vagal response to an extreme stimulus as this one, may, in very rare cases, render per se a cardiac arrest. Hypothermia and extreme stress can both precipitate fatal tachyarrhythmias. A more modern view suggests that an autonomic conflict — sympathetic (due to stress) and parasympathetic (due to the diving reflex) coactivation — may be responsible for some cold water immersion deaths. Gasp reflex and uncontrollable tachypnea can severely increase the risk of water inhalation and drowning.
  
  Some people are much better prepared to survive sudden exposure to very cold water due to body and mental characteristics and due to conditioning. In fact, cold water swimming (also known as ice swimming or winter swimming) is a sport and an activity that reportedly can lead to several health benefits when done regularly. (Full article...)
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  Simplified schematic of only the lunar portion of Earth's tides, showing (exaggerated) high tides at the sublunar point and its antipode for the hypothetical case of an ocean of constant depth without land, and on the assumption that Earth is not rotating; otherwise there is a lag angle. Solar tides not shown.

  
  Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another.
  
  Tide tables can be used for any given locale to find the predicted times and amplitude (or "tidal range").
  The predictions are influenced by many factors including the alignment of the Sun and Moon, the phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see Timing). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude tides a day—is a third regular category.
  
  Tides vary on timescales ranging from hours to years due to a number of factors, which determine the lunitidal interval. To make accurate records, tide gauges at fixed stations measure water level over time. Gauges ignore variations caused by waves with periods shorter than minutes. These data are compared to the reference (or datum) level usually called mean sea level.
  
  While tides are usually the largest source of short-term sea-level fluctuations, sea levels are also subject to change from thermal expansion, wind, and barometric pressure changes, resulting in storm surges, especially in shallow seas and near coasts.
  
  Tidal phenomena are not limited to the oceans, but can occur in other systems whenever a gravitational field that varies in time and space is present. For example, the shape of the solid part of the Earth is affected slightly by Earth tide, though this is not as easily seen as the water tidal movements. (Full article...)

Профессиональный дайвинг

Указатель профессионального дайвинга

• Image 1

  Дайвмастер (DM) — это должность, которая включает в себя организацию и руководство рекреационными погружениями, особенно в профессиональном качестве, и это квалификация , используемая во многих частях мира в рекреационном подводном плавании с аквалангом для дайвера, несущего руководящую ответственность за группу дайверов и в качестве дайв-гида. «Дайвмастер» - это не только общий термин, но и название первого профессионального рейтинга многих учебных агентств , таких как PADI , SSI , SDI , NASE , за исключением NAUI , который оценивает дайвмастера NAUI под руководством инструктора NAUI, но выше уровня NAUI. Помощник инструктора. Сертификация дайвмастера обычно эквивалентна требованиям ISO  24801-3 Dive Leader .
  
  BSAC признает сертификаты дайвмастера некоторых агентств эквивалентными BSAC Dive Leader, но не BSAC Advanced Diver . Обратное может быть неверным.
  
  Сертификация является обязательным условием для обучения в качестве инструктора по рекреационному дайвингу в профессиональных агентствах, за исключением NAUI , где это необязательный шаг из-за другого положения дайвмастера NAUI в иерархии NAUI. ( Полная статья... )
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  Scuba diving education levels as used by ISO, PADI, CMAS, SSI and NAUI

  
  Recreational diver training is the process of developing knowledge and understanding of the basic principles, and the skills and procedures for the use of scuba equipment so that the diver is able to dive for recreational purposes with acceptable risk using the type of equipment and in similar conditions to those experienced during training.
  
  Not only is the underwater environment hazardous but the diving equipment itself can be dangerous. There are problems that divers must learn to avoid and manage when they do occur. Divers need repeated practice and a gradual increase in challenge to develop and internalise the skills needed to control the equipment, to respond effective if they encounter difficulties, and to build confidence in their equipment and themselves. Diver practical training starts with simple but essential procedures, and builds on them until complex procedures can be managed effectively. This may be broken up into several short training programmes, with certification issued for each stage, or combined into a few more substantial programmes with certification issued when all the skills have been mastered.
  
  Many diver training organizations exist, throughout the world, offering diver training leading to certification: the issuing of a "diving certification card," also known as a "C-card," or qualification card. This diving certification model originated at Scripps Institution of Oceanography in 1952 after two divers died while using university-owned equipment and the SIO instituted a system where a card was issued after training as evidence of competence. Diving instructors affiliated to a diving certification agency may work independently or through a university, a dive club, a dive school or a dive shop. They will offer courses that should meet, or exceed, the standards of the certification organization that will certify the divers attending the course. The International Organization for Standardization has approved six recreational diving standards that may be implemented worldwide, and some of the standards developed by the (United States) RSTC are consistent with the applicable ISO Standards:
  
  The initial open water training for a person who is medically fit to dive and a reasonably competent swimmer is relatively short. Many dive shops in popular holiday locations offer courses intended to teach a novice to dive in a few days, which can be combined with diving on the vacation. Other instructors and dive schools will provide more thorough training, which generally takes longer. Dive operators, dive shops, and cylinder filling stations may refuse to allow uncertified people to dive with them, hire diving equipment or have their diving cylinders filled. This may be an agency standard, company policy, or specified by legislation. (Full article...)
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  A US Navy diver at work. The umbilical supplying air from the surface is clearly visible.

  
  
  Professional diving is underwater diving where the divers are paid for their work. Occupational diving has a similar meaning and applications. The procedures are often regulated by legislation and codes of practice as it is an inherently hazardous occupation and the diver works as a member of a team. Due to the dangerous nature of some professional diving operations, specialized equipment such as an on-site hyperbaric chamber and diver-to-surface communication system is often required by law, and the mode of diving for some applications may be regulated.
  
  There are several branches of professional diving, the best known of which is probably commercial diving and its specialised applications, offshore diving, inshore civil engineering diving, marine salvage diving, hazmat diving, and ships husbandry diving. There are also applications in scientific research, marine archaeology, fishing and aquaculture, public service, law enforcement, military service, media work and diver training.
  
  Any person wishing to become a professional diver normally requires specific training that satisfies any regulatory agencies which have regional or national authority, such as US Occupational Safety and Health Administration, United Kingdom Health and Safety Executive or South African Department of Employment and Labour. International recognition of professional diver qualifications and registration exists between some countries. (Full article...)
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  US Navy diver dredging an excavation site during an underwater recovery operation, searching for personnel who went missing during WWII off the coast of Koror

  
  
  Salvage diving is the diving work associated with the recovery of all or part of ships, their cargoes, aircraft, and other vehicles and structures which have sunk or fallen into water. In the case of ships it may also refer to repair work done to make an abandoned or distressed but still floating vessel more suitable for towing or propulsion under its own power. The recreational/technical activity known as wreck diving is generally not considered salvage work, though some recovery of artifacts may be done by recreational divers.
  
  Most salvage diving is commercial work, or military work, depending on the diving contractor and the purpose for the salvage operation, Similar underwater work may be done by divers as part of forensic investigations into accidents, in which case the procedures may be more closely allied with underwater archaeology than the more basic procedures of advantageous cost/benefit expected in commercial and military operations.
  
  Clearance diving, the removal of obstructions and hazards to navigation, is closely related to salvage diving, but has a different purpose, in that the objects to be removed are not intended to be recovered, just removed or reduced to a condition where they no longer constitute a hazard or obstruction. Many of the techniques and procedures used in clearance diving are also used in salvage work. (Full article...)
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  A US Navy work diver is lowered to the sea bed during a dive from the USNS Grasp (T-ARS-51) off the coast of St. Kitts.

  
  A clearance diver was originally a specialist naval diver who used explosives underwater to remove obstructions to make harbours and shipping channels safe to navigate, but the term "clearance diver" was later used to include other naval underwater work. Units of clearance divers were first formed during and after World War II to clear ports and harbours in the Mediterranean and Northern Europe of unexploded ordnance and shipwrecks and booby traps laid by the Germans. (Full article...)
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  A United States Navy Mass Communication Specialist conducting underwater photography training

  
  Underwater photography is the process of taking photographs while under water. It is usually done while scuba diving, but can be done while diving on surface supply, snorkeling, swimming, from a submersible or remotely operated underwater vehicle, or from automated cameras lowered from the surface.
  
  Underwater photography can also be categorised as an art form and a method for recording data.
  Successful underwater imaging is usually done with specialized equipment and techniques. However, it offers exciting and rare photographic opportunities. Animals such as fish and marine mammals are common subjects, but photographers also pursue shipwrecks, submerged cave systems, underwater "landscapes", invertebrates, seaweeds, geological features, and portraits of fellow divers. (Full article...)
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  NYPD divers removing material from the Harlem Meer following a murder in the area few days prior.

  
  Police diving is a branch of professional diving carried out by police services. Police divers are usually professional police officers, and may either be employed full-time as divers or as general water police officers, or be volunteers who usually serve in other units but are called in if their diving services are required.
  
  The duties carried out by police divers include rescue diving for underwater casualties, under the general classification of public safety diving, and forensic diving, which is search and recovery diving for evidence and bodies. (Full article...)
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  A SEAL Delivery Team member climbs aboard a delivery vehicle before launching from the back of the submarine USS Philadelphia.

  
  
  A frogman is someone who is trained in scuba diving or swimming underwater in a tactical capacity that includes military, and in some European countries, police work. Such personnel are also known by the more formal names of combat diver, combatant diver, or combat swimmer. The word frogman first arose in the stage name the "Fearless Frogman" of Paul Boyton in the 1870s and later was claimed by John Spence, an enlisted member of the U.S. Navy and member of the OSS Maritime Unit, to have been applied to him while he was training in a green waterproof suit.
  
  The term frogman is occasionally used to refer to a civilian scuba diver. Some sport diving clubs include the word frogmen in their names. The preferred term by scuba users is diver, but the frogman epithet persists in informal usage by non-divers, especially in the media and often refers to professional scuba divers, such as in a police diving role.
  
  In the U.S. military and intelligence community, divers trained in scuba or CCUBA who deploy for tactical assault missions are called "combat divers". This term is used to commonly refer to Navy UDTs, Navy SEALs, Navy SARC, and the Navy Explosive Ordnance Disposal (EOD) units. Navy SWCC have frogmen heritage of combat swimming rather than diving, one of the few and most elite units trained in this element. Other frogmen units include marine raiders marine recon, elements of US Army Special Forces (aka Green Berets) combat divers, Army Rangers Regimental Reconnaissance Company, Air Force Pararescue, Air Force Combat Controllers, and Air Force Special Reconnaissance, as well as operatives of the CIA's Special Activities Center.
  
  In the United Kingdom, police divers have often been called "police frogmen".
  
  Some countries' tactical diver organizations include a translation of the word frogman in their official names, e.g., Denmark's Frømandskorpset; others call themselves "combat divers" or similar. Others call themselves by indefinite names such as "special group 13" and "special operations unit".
  
  Many nations and some irregular armed groups deploy or have deployed combat swimmers or divers. (Full article...)
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  An ama pearl diver in Japan

  
  Pearl hunting, also known as pearling, is the activity of recovering or attempting to recover pearls from wild molluscs, usually oysters or mussels, in the sea or freshwater. Pearl hunting was prevalent in the Persian Gulf region and Japan for thousands of years. On the northern and north-western coast of Western Australia pearl diving began in the 1850s, and started in the Torres Strait Islands in the 1860s, where the term also covers diving for nacre or mother of pearl found in what were known as pearl shells.
  
  In most cases the pearl-bearing molluscs live at depths where they are not manually accessible from the surface, and diving or the use of some form of tool is needed to reach them. Historically the molluscs were retrieved by freediving, a technique where the diver descends to the bottom, collects what they can, and surfaces on a single breath. The diving mask improved the ability of the diver to see while underwater. When the surface-supplied diving helmet became available for underwater work, it was also applied to the task of pearl hunting, and the associated activity of collecting pearl shell as a raw material for the manufacture of buttons, inlays and other decorative work. The surface supplied diving helmet greatly extended the time the diver could stay at depth, and introduced the previously unfamiliar hazards of barotrauma of ascent and decompression sickness. (Full article...)
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  Public safety diving team members bring in a casualty

  
  Underwater search and recovery is the process of locating and recovering underwater objects, often by divers, but also by the use of submersibles, remotely operated vehicles and electronic equipment on surface vessels.
  
  Most underwater search and recovery is done by professional divers as part of commercial marine salvage operations, military operations, emergency services, or law enforcement activities.
  
  Minor aspects of search and recovery are also considered within the scope of recreational diving. (Full article...)
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  Drawing to scale, underwater

  
  Underwater archaeology is archaeology practiced underwater. As with all other branches of archaeology, it evolved from its roots in pre-history and in the classical era to include sites from the historical and industrial eras.
  
  Its acceptance has been a relatively late development due to the difficulties of accessing and working underwater sites, and because the application of archaeology to underwater sites initially emerged from the skills and tools developed by shipwreck salvagers. As a result, underwater archaeology initially struggled to establish itself as actual archaeological research. This changed when universities began teaching the subject and a theoretical and practical base for the sub-discipline was firmly established in the late 1980s.
  
  Underwater archaeology now has a number of branches including, maritime archaeology: the scientifically based study of past human life, behaviours and cultures and their activities in, on, around and (lately) under the sea, estuaries and rivers. This is most often effected using the physical remains found in, around or under salt or fresh water or buried beneath water-logged sediment. In recent years, the study of submerged WWII sites and of submerged aircraft in the form of underwater aviation archaeology have also emerged as bona fide activity.
  
  Though often mistaken as such, underwater archaeology is not restricted to the study of shipwrecks. Changes in sea level because of local seismic events such as the earthquakes that devastated Port Royal and Alexandria or more widespread climatic changes on a continental scale mean that some sites of human occupation that were once on dry land are now submerged. At the end of the last ice age, the North Sea was a great plain, and anthropological material, as well as the remains of animals such as mammoths, are sometimes recovered by trawlers. Also, because human societies have always made use of water, sometimes the remains of structures that these societies built underwater still exist (such as the foundations of crannogs, bridges and harbours) when traces on dry land have been lost. As a result, underwater archaeological sites cover a vast range including: submerged indigenous sites and places where people once lived or visited that have been subsequently covered by water due to rising sea levels; wells, cenotes, wrecks (shipwrecks; aircraft); the remains of structures created in water (such as crannogs, bridges or harbours); other port-related structures; refuse or debris sites where people disposed of their waste, garbage and other items, such as ships, aircraft, munitions and machinery, by dumping into the water.
  
  Underwater archaeology is often complementary to archaeological research on terrestrial sites because the two are often linked by many and various elements including geographic, social, political, economic and other considerations. As a result, a study of an archaeological landscape can involve a multidisciplinary approach requiring the inclusion of many specialists from a variety of disciplines including prehistory, historical archaeology, maritime archaeology, and anthropology. There are many examples. One is the wreck of the VOC ship Zuytdorp lost in 1711 on the coast of Western Australia, where there remains considerable speculation that some of the crew survived and, after establishing themselves on shore, intermixed with indigenous tribes from the area. The archaeological signature at this site also now extends into the interaction between indigenous people and the European pastoralists who entered the area in the mid-19th century. (Full article...)
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  Underwater welding

  
  Hyperbaric welding is the process of extreme welding at elevated pressures, normally underwater. Hyperbaric welding can either take place wet in the water itself or dry inside a specially constructed positive pressure enclosure and hence a dry environment. It is predominantly referred to as "hyperbaric welding" when used in a dry environment, and "underwater welding" when in a wet environment. The applications of hyperbaric welding are diverse—it is often used to repair ships, offshore oil platforms, and pipelines. Steel is the most common material welded.
  
  Dry welding is used in preference to wet underwater welding when high quality welds are required because of the increased control over conditions which can be maintained, such as through application of prior and post weld heat treatments. This improved environmental control leads directly to improved process performance and a generally much higher quality weld than a comparative wet weld. Thus, when a very high quality weld is required, dry hyperbaric welding is normally utilized. Research into using dry hyperbaric welding at depths of up to 1,000 metres (3,300 ft) is ongoing. In general, assuring the integrity of underwater welds can be difficult (but is possible using various nondestructive testing applications), especially for wet underwater welds, because defects are difficult to detect if the defects are beneath the surface of the weld.
  
  Underwater hyperbaric welding was invented by the Soviet metallurgist Konstantin Khrenov in 1932. (Full article...)
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  Surface supplied diving equipment on display

  
  
  Commercial offshore diving, sometimes shortened to just offshore diving, generally refers to the branch of commercial diving, with divers working in support of the exploration and production sector of the oil and gas industry in places such as the Gulf of Mexico in the United States, the North Sea in the United Kingdom and Norway, and along the coast of Brazil. The work in this area of the industry includes maintenance of oil platforms and the building of underwater structures. In this context "offshore" implies that the diving work is done outside of national boundaries. Technically it also refers to any diving done in the international offshore waters outside of the territorial waters of a state, where national legislation does not apply. Most commercial offshore diving is in the Exclusive Economic Zone of a state, and much of it is outside the territorial waters. Offshore diving beyond the EEZ does also occur, and is often for scientific purposes.
  
  Equipment used for commercial offshore diving tends to be surface supplied equipment but this varies according to the work and location. For instance, divers in the Gulf of Mexico may use wetsuits whilst North Sea divers need dry suits or even hot water suits because of the low temperature of the water.
  
  Diving work in support of the offshore oil and gas industries is usually contract based.
  
  Saturation diving is standard practice for bottom work at many of the deeper offshore sites, and allows more effective use of the diver's time while reducing the risk of decompression sickness. Surface oriented air diving is more usual in shallower water. (Full article...)
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  Sponge diver putting on his diving suit in Tarpon Springs, Florida.

  
  
  Sponge diving is underwater diving to collect soft natural sponges for human use. (Full article...)
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  Underwater videographer

  
  Underwater videography is the branch of electronic underwater photography concerned with capturing underwater moving images as a recreational diving, scientific, commercial, documentary, or filmmaking activity. (Full article...)

Рекреационный дайвинг

Указатель любительского дайвинга

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  ДИР-дайверы

  
  
  Doing It Right ( DIR ) — это целостный подход к подводному плаванию с аквалангом , который включает в себя несколько важных элементов, включая фундаментальные навыки дайвинга, командную работу, физическую подготовку, а также оптимизированные и минималистичные конфигурации оборудования. Сторонники DIR утверждают, что благодаря этим элементам безопасность повышается за счет стандартизации конфигурации оборудования и процедур дайв-групп по предотвращению и устранению чрезвычайных ситуаций.
  
  DIR возник в результате усилий дайверов, участвовавших в проекте «Карстовая равнина Вудвилля » (WKPP) в 1990-х годах, которые искали способы снизить уровень смертности в этих пещерных системах. Философия DIR в настоящее время используется в качестве основы для обучения подводному плаванию с аквалангом от начального уровня до технической и пещерной квалификации несколькими организациями , такими как Global Underwater Explorers (GUE), Unified Team Diving (UTD) и InnerSpace Explorers (ISE). ( Полная статья... )
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  Below is the list of current British records in finswimming. The records are ratified by the British Finswimming Association.
  
  This list echoes that found on the Monofin website. These records are correct as of 1 April 2018.
  
  In December 2017 British Finswimming Association made a decision to maintain the National records separately for adults and juniors in line with CMAS regulations. (Full article...)
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  Underwater sports is a group of competitive sports using one or a combination of the following underwater diving techniques - breath-hold, snorkelling or scuba, usually including the use of equipment such as diving masks and fins. These sports are conducted in the natural environment at sites such as open water and sheltered or confined water such as lakes and in artificial aquatic environments such as swimming pools. Underwater sports include the following - aquathlon (i.e. underwater wrestling), finswimming, freediving, spearfishing, sport diving, underwater football, underwater hockey, underwater ice hockey, underwater orienteering, underwater photography, underwater rugby, underwater target shooting and underwater video. (Full article...)
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  A United States Navy Mass Communication Specialist conducting underwater photography training

  
  Underwater photography is the process of taking photographs while under water. It is usually done while scuba diving, but can be done while diving on surface supply, snorkeling, swimming, from a submersible or remotely operated underwater vehicle, or from automated cameras lowered from the surface.
  
  Underwater photography can also be categorised as an art form and a method for recording data.
  Successful underwater imaging is usually done with specialized equipment and techniques. However, it offers exciting and rare photographic opportunities. Animals such as fish and marine mammals are common subjects, but photographers also pursue shipwrecks, submerged cave systems, underwater "landscapes", invertebrates, seaweeds, geological features, and portraits of fellow divers. (Full article...)
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  Sport diving is an underwater sport that uses recreational open circuit scuba diving equipment and consists of a set of individual and team events conducted in a swimming pool that test the competitors' competency in recreational scuba diving techniques. The sport was developed in Spain during the late 1990s and is currently played mainly in Europe. It is known as Plongée Sportive en Piscine in French and as Buceo De Competición in Spanish. (Full article...)
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  Spearfisher Monument in Croatia

  
  
  Spearfishing is fishing using handheld elongated, sharp-pointed tools such as a spear, gig, or harpoon, to impaling the fish in the body. It was one of the earliest fishing techniques used by mankind, and has been deployed in artisanal fishing throughout the world for millennia. Early civilizations were familiar with the custom of spearing fish from rivers and streams using sharpened sticks.
  
  Modern spearfishing usually involves the use of underwater swimming gear and slingshot-like elastic spearguns or compressed gas powered pneumatic spearguns, which launch a tethered dart-like projectile to strike the target fish. Specialised techniques and equipment have been developed for various types of aquatic environments and target fish. Spearfishing uses no bait and is highly selective, with no by-catch, but inflicts lethal injury to the fish and thus precludes catch and release.
  
  Spearfishing may be done using free-diving, snorkelling, or scuba diving techniques, but spearfishing while using scuba equipment is illegal in some countries. The use of mechanically powered spearguns is also outlawed in some countries and jurisdictions such as New Zealand. (Full article...)
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  Diver Trevor Jackson returning from a 600 ft (183 m) dive

  
  Technical diving (also referred to as tec diving or tech diving) is scuba diving that exceeds the agency-specified limits of recreational diving for non-professional purposes. Technical diving may expose the diver to hazards beyond those normally associated with recreational diving, and to a greater risk of serious injury or death. The risk may be reduced by appropriate skills, knowledge and experience, and by using suitable equipment and procedures. The skills may be developed through appropriate specialised training and experience. The equipment involves breathing gases other than air or standard nitrox mixtures, and multiple gas sources.
  
  The popularisation of the term technical diving has been credited to Michael Menduno, who was editor of the (now defunct) diving magazine aquaCorps Journal, but the concept and term, technical diving, go back at least as far as 1977, and divers have been engaging in what is now commonly referred to as technical diving for decades. (Full article...)
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  Below is the list of current United States of America Fin Swimming National Records. The records are ratified by the Underwater Society of America and USA Fin Swimming. (Full article...)
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  Underwater orienteering is an underwater sport that uses recreational open circuit scuba diving equipment and consists of a set of individual and team events conducted in both sheltered and open water testing the competitors' competency in underwater navigation. The competition is principally concerned with the effectiveness of navigation technique used by competitors to swim an underwater course following a route marked on a map prepared by the competition organisers, a compass and a counter meter to measure the distance covered. The sport was developed in the Soviet Union during the late 1950s and is played mainly in Europe. It is known as Orientation Sub in French and as La Orientación Subacuática in Spanish. Historically, the sport has also been known as Technical Disciplines. (Full article...)
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  Finswimming with monofin

  
  Finswimming is an underwater sport consisting of four techniques involving swimming with the use of fins either on the water's surface using a snorkel with either monofins or bifins or underwater with monofin either by holding one's breath or using open circuit scuba diving equipment. Events exist over distances similar to swimming competitions for both swimming pool and open water venues. Competition at world and continental level is organised by the Confédération Mondiale des Activités Subaquatiques (CMAS). The sport's first world championship was held in 1976. It also has been featured at the World Games as a trend sport since 1981 and was demonstrated at the 2015 European Games in June 2015. (Full article...)
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  Below is the list of current Commonwealth Records for finswimming. The records are ratified by the Commonwealth Finswimming Committee, which is made up of the National Finswimming Governing Bodies of Commonwealth of Nations. The First Commonwealth Championships were held in Hobart, Tasmania, Australia in February 2007.
  
  This page does not include the Commonwealth Finswimming Championship Records. This list echoes that found on the Swansea Finswimming Club Website and the British Finswimming Association documents website. These records are correct as of 4 December 2008.
  Times set before the First Commonwealth Championships have been allowed. All records have been accepted as a result of documentary evidence of the events or time-trials that they were set at.
  
  Currently there are only four nations hold records: Australia (10), England (8), New Zealand (7) and Singapore (5). Finswimming is currently competed in eight Commonwealth Countries (including home nations); Australia, Canada, Cyprus, England, New Zealand, Scotland, Singapore, South Africa and Wales (). (Full article...)
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  Underwater rugby match in Norway.

  
  Underwater rugby (UWR) is an underwater team sport. During a match two teams try to score a negatively buoyant ball (filled with saltwater) into the opponents’ goal at the bottom of a swimming pool. It originated from within the physical fitness training regime existing in German diving clubs during the early 1960s and has little in common with rugby football except for the name. It was recognised by the Confédération Mondiale des Activités Subaquatiques (CMAS) in 1978 and was first played as a world championship in 1980. (Full article...)
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  Divers Alert Network (DAN) is a group of not-for-profit organisations dedicated to improving diving safety for all divers. It was founded in Durham, North Carolina, USA in 1980 at Duke University to provide 24/7 telephonic hotline diving medical assistance. Since then the organisation has expanded globally and now has independent regional organisations in North America, Europe, Japan, Asia-Pacific and Southern Africa.
  
  DAN publishes research results on a wide range of matters relating to diving safety and medicine and diving accident analysis, including annual reports on decompression illness and diving fatalities. Most are freely available on the internet, many of these at the Rubicon Research Repository.
  
  This list includes publications where one or more authors are staff or members of one of the DAN affiliates, where a large part of the data is from one of the DAN Databases, or where the research was funded by DAN. (Full article...)
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  Below is the list of current European finswimming records. The records are ratified by the CMAS Confédération Mondiale des Activités Subaquatiques (World Underwater Federation). (Full article...)
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  A cave diver running a reel with guide line into the overhead environment

  
  
  Cave-diving is underwater diving in water-filled caves. It may be done as an extreme sport, a way of exploring flooded caves for scientific investigation, or for the search for and recovery of divers or, as in the 2018 Thai cave rescue, other cave users. The equipment used varies depending on the circumstances, and ranges from breath hold to surface supplied, but almost all cave-diving is done using scuba equipment, often in specialised configurations with redundancies such as sidemount or backmounted twinset. Recreational cave-diving is generally considered to be a type of technical diving due to the lack of a free surface during large parts of the dive, and often involves planned decompression stops. A distinction is made by recreational diver training agencies between cave-diving and cavern-diving, where cavern diving is deemed to be diving in those parts of a cave where the exit to open water can be seen by natural light. An arbitrary distance limit to the open water surface may also be specified.
  
  Equipment, procedures, and the requisite skills have been developed to reduce the risk of becoming lost in a flooded cave, and consequently drowning when the breathing gas supply runs out. The equipment aspect largely involves the provision of an adequate breathing gas supply to cover reasonably foreseeable contingencies, redundant dive lights and other safety critical equipment, and the use of a continuous guideline leading the divers back out of the overhead environment. The skills and procedures include effective management of the equipment, and procedures to recover from foreseeable contingencies and emergencies, both by individual divers, and by the teams that dive together.
  
  In the United Kingdom, cave-diving developed from the locally more common activity of caving. Its origins in the United States are more closely associated with recreational scuba diving. Compared to caving and scuba diving, there are relatively few practitioners of cave-diving. This is due in part to the specialized equipment and skill sets required, and in part because of the high potential risks due to the specific environment.
  
  Despite these risks, water-filled caves attract scuba divers, cavers, and speleologists due to their often unexplored nature, and present divers with a technical diving challenge. Underwater caves have a wide range of physical features, and can contain fauna not found elsewhere. Several organisations dedicated to cave diving safety and exploration exist, and several agencies provide specialised training in the skills and procedures considered necessary for acceptable safety. (Full article...)

Опасности, инциденты, безопасность и закон при дайвинге

Индекс безопасности дайвинга

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  Дайверы сталкиваются с особыми физическими рисками и рисками для здоровья , когда они погружаются под воду с аквалангом или другим снаряжением для дайвинга или используют дыхательный газ под высоким давлением . Некоторые из этих факторов также влияют на людей, которые работают в условиях повышенного давления вне воды, например, в кессонах . В этой статье перечислены опасности, которым может подвергнуться дайвер во время погружения, и возможные последствия этих опасностей, а также некоторые подробности непосредственных причин перечисленных последствий. Также дан список мер предосторожности, которые можно принять для снижения уязвимости либо за счет снижения риска, либо за счет смягчения последствий. Понимаемая и признанная опасность может представлять меньший риск, если приняты соответствующие меры предосторожности, а последствия могут быть менее серьезными, если спланированы и внедрены процедуры смягчения последствий.
  
  Опасность – это любой агент или ситуация, представляющая определенный уровень угрозы для жизни, здоровья, имущества или окружающей среды. Большинство опасностей остаются дремлющими или потенциальными, имея лишь теоретический риск причинения вреда, а когда опасность становится активной и приводит к нежелательным последствиям, это называется инцидентом и может привести к чрезвычайной ситуации или несчастному случаю. Опасность и уязвимость взаимодействуют с вероятностью возникновения, создавая риск, который может представлять собой вероятность конкретного нежелательного последствия конкретной опасности или совокупную вероятность нежелательных последствий всех опасностей конкретной деятельности. Наличие комбинации нескольких опасностей одновременно является обычным явлением в дайвинге, и в результате обычно увеличивается риск для дайвера, особенно когда возникновение инцидента, вызванного одной опасностью, вызывает другие опасности с последующим каскадом инцидентов. Многие смертельные случаи при дайвинге являются результатом каскада инцидентов, которые подавляют дайвера, который должен быть в состоянии справиться с любым единичным разумно предсказуемым инцидентом . Оцененный риск погружения обычно считается неприемлемым, если от дайвера не ожидается, что он справится с каким-либо одним разумно предсказуемым инцидентом со значительной вероятностью возникновения во время этого погружения. Где именно будет проведена линия, зависит от обстоятельств. Коммерческие дайверы, как правило, менее терпимы к риску, чем рекреационные, особенно технические дайверы, которые менее ограничены законодательством в области охраны труда и техники безопасности .
  
  Декомпрессионная болезнь и артериальная газовая эмболия при любительском дайвинге связаны с определенными демографическими факторами, факторами окружающей среды и стилем погружения. Статистическое исследование, опубликованное в 2005 году, проверяло потенциальные факторы риска: возраст, пол, индекс массы тела, курение, астма, диабет, сердечно-сосудистые заболевания, предыдущая декомпрессионная болезнь, годы с момента сертификации, погружения в прошлом году, количество дней погружений, количество погружений в прошлом году. повторяющаяся серия, глубина последнего погружения, использование найтрокса и использование сухого костюма. Никакой значимой связи с астмой, диабетом, сердечно-сосудистыми заболеваниями, курением или индексом массы тела с декомпрессионной болезнью или артериальной газовой эмболией не обнаружено. Повышенная глубина, предыдущая DCI, многодневные погружения и принадлежность к мужскому полу были связаны с более высоким риском декомпрессионной болезни и артериальной газовой эмболии. Использование найтрокса и сухих костюмов, более частые погружения в прошлом году, возраст и годы, прошедшие после сертификации, были связаны с меньшим риском, возможно, как показатели более обширной подготовки и опыта.
  
  Статистические данные показывают, что число смертельных случаев при дайвинге сопоставимо с автомобильными авариями: 16,4 на 100 000 дайверов и 16 на 100 000 водителей. Данные Divers Alert Network за 2014 год показывают, что в Америке насчитывается 3,174 миллиона дайверов-любителей , из которых 2,351 миллиона погружаются от 1 до 7 раз в год и 823 000 погружаются 8 или более раз в год. Разумно предположить, что в среднем будет около 5 погружений в год. ( Полная статья... )
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  Infographic by NIOSH. Control methods at the top of graphic are potentially more effective and protective than those at the bottom. Following this hierarchy normally leads to the implementation of inherently safer systems, where the risk of illness or injury has been substantially reduced.

  
  Hierarchy of hazard control is a system used in industry to prioritize possible interventions to minimize or eliminate exposure to hazards. It is a widely accepted system promoted by numerous safety organizations. This concept is taught to managers in industry, to be promoted as standard practice in the workplace. It has also been used to inform public policy, in fields such as road safety. Various illustrations are used to depict this system, most commonly a triangle.
  
  The hazard controls in the hierarchy are, in order of decreasing priority:

  • Elimination
  • Substitution
  • Engineering controls
  • Administrative controls
  • Personal protective equipment

  
  The priority should not be confused with effectiveness. The system is not based on evidence about effectiveness but based on the assumed burden on workers. If elimination of the hazard is possible, it frees workers of being aware of the hazard and protecting themselves. That is the basis for the priority. Substitution has less priority than elimination because the substitute can possibly also come with a hazard. Engineering controls depend on a well-functioning system and human behaviour. Administrative controls and personal protective equipment are always dependent on human behaviour which makes these controls less reliable. (Full article...)
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  Folding lockout hasp, allowing the use of up to six padlocks to secure a device.

  
  Lock out, tag out or lockout–tagout (LOTO) is a safety procedure used to ensure that dangerous equipment is properly shut off and not able to be started up again prior to the completion of maintenance or repair work. It requires that hazardous energy sources be "isolated and rendered inoperative" before work is started on the equipment in question. The isolated power sources are then locked and a tag is placed on the lock identifying the worker and reason the LOTO is placed on it. The worker then holds the key for the lock, ensuring that only they can remove the lock and start the equipment. This prevents accidental startup of equipment while it is in a hazardous state or while a worker is in direct contact with it.
  
  Lockout–tagout is used across industries as a safe method of working on hazardous equipment and is mandated by law in some countries. (Full article...)
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  Scuba diving fatalities are deaths occurring while scuba diving or as a consequence of scuba diving. The risks of dying during recreational, scientific or commercial diving are small, and on scuba, deaths are usually associated with poor gas management, poor buoyancy control, equipment misuse, entrapment, rough water conditions and pre-existing health problems. Some fatalities are inevitable and caused by unforeseeable situations escalating out of control, though the majority of diving fatalities can be attributed to human error on the part of the victim.
  
  Equipment failure is rare in open circuit scuba, and while the cause of death is commonly recorded as drowning, this is mainly the consequence of an uncontrollable series of events taking place in water. Arterial gas embolism is also frequently cited as a cause of death, and it, too, is the consequence of other factors leading to an uncontrolled and badly managed ascent, possibly aggravated by medical conditions. About a quarter of diving fatalities are associated with cardiac events, mostly in older divers. There is a fairly large body of data on diving fatalities, but in many cases, the data is poor due to the standard of investigation and reporting. This hinders research that could improve diver safety.
  
  For diving facilities, scuba diving fatalities have a major financial impact by way of lost income, lost business, insurance premium increases and high litigation costs. (Full article...)
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  This list identifies the legislation governing underwater diving activities listed by region. Some legislation affects only professional diving, other may affect only recreational diving, or all diving activities. The list includes primary and delegated legislation, and international standards for the conduct of diving adopted by national states, but does not include legislation or standards relating to manufacture or testing of diving equipment. (Full article...)
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  Diving safety is the aspect of underwater diving operations and activities concerned with the safety of the participants. The safety of underwater diving depends on four factors: the environment, the equipment, behaviour of the individual diver and performance of the dive team. The underwater environment can impose severe physical and psychological stress on a diver, and is mostly beyond the diver's control. Equipment is used to operate underwater for anything beyond very short periods, and the reliable function of some of the equipment is critical to even short-term survival. Other equipment allows the diver to operate in relative comfort and efficiency, or to remain healthy over the longer term. The performance of the individual diver depends on learned skills, many of which are not intuitive, and the performance of the team depends on competence, communication, attention and common goals.
  
  There is a large range of hazards to which the diver may be exposed. These each have associated consequences and risks, which should be taken into account during dive planning. Where risks are marginally acceptable it may be possible to mitigate the consequences by setting contingency and emergency plans in place, so that damage can be minimised where reasonably practicable. The acceptable level of risk varies depending on legislation, codes of practice, company policy, and personal choice, with recreational divers having a greater freedom of choice.
  
  In professional diving there is a diving team to support the diving operation, and their primary function is to reduce and mitigate risk to the diver. The diving supervisor for the operation is legally responsible for the safety of the diving team. A diving contractor may have a diving superintendent or a diving safety officer tasked with ensuring the organisation has, and uses, a suitable operations manual to guide their practices. In recreational diving, the dive leader may be partly responsible for diver safety to the extent that the dive briefing is reasonably accurate and does not omit any known hazards that divers in the group can reasonably be expected to be unaware of, and not to lead the group into a known area of unacceptable risk. A certified recreational diver is generally responsible for their own safety, and to a lesser, variable, and poorly defined extent, for the safety of their dive buddy. (Full article...)
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  A code of practice can be a document that complements occupational health and safety laws and regulations to provide detailed practical guidance on how to comply with legal obligations, and should be followed unless another solution with the same or better health and safety standard is in place, or may be a document for the same purpose published by a self-regulating body to be followed by member organisations.
  
  Codes of practice published by governments do not replace the occupational health and safety laws and regulations, and are generally issued in terms of those laws and regulations. They are intended to help understand how to comply with the requirements of regulations. A workplace inspector can refer to a code of practice when issuing an improvement or prohibition notice, and they may be admissible in court proceedings. A court may use a code of practice to establish what is reasonably practicable action to manage a specific risk. Equivalent or better ways of achieving the required work health and safety may be possible, so compliance with codes of practice is not usually mandatory, providing that any alternative systems used provide a standard of health and safety equal to or better than those recommended by the code of practice.
  
  Organisational codes of practice do not have the same authority under law, but serve a similar purpose. Member organisations generally undertake to comply with the codes of practice as a condition of membership and may lose membership if found to be in violation of the code. (Full article...)
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  The civil liability of a recreational diver may include a duty of care to another diver during a dive. Breach of this duty that is a proximate cause of injury or loss to the other diver may lead to civil litigation for damages in compensation for the injury or loss suffered.
  
  Participation in recreational diving implies acceptance of the inherent risks of the activity Diver training includes training in procedures known to reduce these risks to a level considered acceptable by the certification agency, and issue of certification implies that the agency accepts that the instructor has assessed the diver to be sufficiently competent in these skills at the time of assessment and to be competent to accept the associated risks. Certification relates to a set of skills and knowledge defined by the associated training standard, which also specifies the limitations on the scope of diving activities for which the diver is deemed competent. These limitations involve depth, environment and equipment that the diver has been trained to use. Intentionally diving significantly beyond the scope of certified competence is at the diver's risk, and may be construed as negligence if it puts another person at risk. Recommendations generally suggest that extending the scope should be done gradually, and preferably under the guidance of a diver experienced in similar conditions. The training agencies usually specify that any extension of scope should only be done by further training under a registered instructor, but this is not always practicable, or even possible, as there can always be circumstances that differ from those experienced during training.
  
  Retention of skills requires exercise of those skills, and prolonged periods between dives will degrade skills by unpredictable amounts. This is recognised by training agencies which require instructors to keep in date, and recommend that divers take part in refresher courses after long periods of diving inactivity. (Full article...)
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  Divers face specific physical and health risks when they go underwater with scuba or other diving equipment, or use high pressure breathing gas. Some of these factors also affect people who work in raised pressure environments out of water, for example in caissons. This article lists hazards that a diver may be exposed to during a dive, and possible consequences of these hazards, with some details of the proximate causes of the listed consequences. A listing is also given of precautions that may be taken to reduce vulnerability, either by reducing the risk or mitigating the consequences. A hazard that is understood and acknowledged may present a lower risk if appropriate precautions are taken, and the consequences may be less severe if mitigation procedures are planned and in place.
  
  A hazard is any agent or situation that poses a level of threat to life, health, property, or environment. Most hazards remain dormant or potential, with only a theoretical risk of harm, and when a hazard becomes active, and produces undesirable consequences, it is called an incident and may culminate in an emergency or accident. Hazard and vulnerability interact with likelihood of occurrence to create risk, which can be the probability of a specific undesirable consequence of a specific hazard, or the combined probability of undesirable consequences of all the hazards of a specific activity. The presence of a combination of several hazards simultaneously is common in diving, and the effect is generally increased risk to the diver, particularly where the occurrence of an incident due to one hazard triggers other hazards with a resulting cascade of incidents. Many diving fatalities are the result of a cascade of incidents overwhelming the diver, who should be able to manage any single reasonably foreseeable incident. The assessed risk of a dive would generally be considered unacceptable if the diver is not expected to cope with any single reasonably foreseeable incident with a significant probability of occurrence during that dive. Precisely where the line is drawn depends on circumstances. Commercial diving operations tend to be less tolerant of risk than recreational, particularly technical divers, who are less constrained by occupational health and safety legislation.
  
  Decompression sickness and arterial gas embolism in recreational diving are associated with certain demographic, environmental, and dive style factors. A statistical study published in 2005 tested potential risk factors: age, gender, body mass index, smoking, asthma, diabetes, cardiovascular disease, previous decompression illness, years since certification, dives in last year, number of diving days, number of dives in a repetitive series, last dive depth, nitrox use, and drysuit use. No significant associations with decompression sickness or arterial gas embolism were found for asthma, diabetes, cardiovascular disease, smoking, or body mass index. Increased depth, previous DCI, days diving, and being male were associated with higher risk for decompression sickness and arterial gas embolism. Nitrox and drysuit use, greater frequency of diving in the past year, increasing age, and years since certification were associated with lower risk, possibly as indicators of more extensive training and experience.
  
  Statistics show diving fatalities comparable to motor vehicle accidents of 16.4 per 100,000 divers and 16 per 100,000 drivers. Divers Alert Network 2014 data shows there are 3.174 million recreational scuba divers in America, of which 2.351 million dive 1 to 7 times per year and 823,000 dive 8 or more times per year. It is reasonable to say that the average would be in the neighbourhood of 5 dives per year. (Full article...)
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  A job safety analysis (JSA) is a procedure that helps integrate accepted safety and health principles and practices into a particular task or job operation. The goal of a JSA is to identify potential hazards of a specific role and recommend procedures to control or prevent these hazards.
  
  Other terms often used to describe this procedure are job hazard analysis (JHA), hazardous task analysis (HTA) and job hazard breakdown.
  
  The terms "job" and "task" are commonly used interchangeably to mean a specific work assignment. Examples of work assignments include "operating a grinder," "using a pressurized water extinguisher" or "changing a flat tire." Each of these tasks have different safety hazards that can be highlighted and fixed by using the job safety analysis. (Full article...)
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  Usually city government has a duty of care to repair and maintain the sidewalk

  
  
  In tort law, a duty of care is a legal obligation that is imposed on an individual, requiring adherence to a standard of reasonable care to avoid careless acts that could foreseeably harm others, and lead to claim in negligence. It is the first element that must be established to proceed with an action in negligence. The claimant must be able to show a duty of care imposed by law that the defendant has breached. In turn, breaching a duty may subject an individual to liability. The duty of care may be imposed by operation of law between individuals who have no current direct relationship (familial or contractual or otherwise) but eventually become related in some manner, as defined by common law (meaning case law).
  
  Duty of care may be considered a formalisation of the social contract, the established and implicit responsibilities held by individuals/entities towards others within society. It is not a requirement that a duty of care be defined by law, though it will often develop through the jurisprudence of common law. (Full article...)
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  Common redundant power supply

  
  In engineering and systems theory, redundancy is the intentional duplication of critical components or functions of a system with the goal of increasing reliability of the system, usually in the form of a backup or fail-safe, or to improve actual system performance, such as in the case of GNSS receivers, or multi-threaded computer processing.
  
  In many safety-critical systems, such as fly-by-wire and hydraulic systems in aircraft, some parts of the control system may be triplicated, which is formally termed triple modular redundancy (TMR). An error in one component may then be out-voted by the other two. In a triply redundant system, the system has three sub components, all three of which must fail before the system fails. Since each one rarely fails, and the sub components are designed to preclude common failure modes (which can then be modelled as independent failure), the probability of all three failing is calculated to be extraordinarily small; it is often outweighed by other risk factors, such as human error. Electrical surges arising from lightning strikes are an example of a failure mode which is difficult to fully isolate, unless the components are powered from independent power busses and have no direct electrical pathway in their interconnect (communication by some means is required for voting). Redundancy may also be known by the terms "majority voting systems" or "voting logic".
  
  Redundancy sometimes produces less, instead of greater reliability – it creates a more complex system which is prone to various issues, it may lead to human neglect of duty, and may lead to higher production demands which by overstressing the system may make it less safe.
  
  Redundancy is one form of robustness as practiced in computer science.
  
  Geographic redundancy has become important in the data center industry, to safeguard data against natural disasters and political instability (see below). (Full article...)
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  Human factors are the physical or cognitive properties of individuals, or social behavior which is specific to humans, and influence functioning of technological systems as well as human-environment equilibria. The safety of underwater diving operations can be improved by reducing the frequency of human error and the consequences when it does occur. Human error can be defined as an individual's deviation from acceptable or desirable practice which culminates in undesirable or unexpected results.
  
  

  Dive safety is primarily a function of four factors: the environment, equipment, individual diver performance and dive team performance. The water is a harsh and alien environment which can impose severe physical and psychological stress on a diver. The remaining factors must be controlled and coordinated so the diver can overcome the stresses imposed by the underwater environment and work safely. Diving equipment is crucial because it provides life support to the diver, but the majority of dive accidents are caused by individual diver panic and an associated degradation of the individual diver's performance. - M.A. Blumenberg, 1996

  
  
  Human error is inevitable and most errors are minor and do not cause significant harm, but others can have catastrophic consequences. Examples of human error leading to accidents are available in vast numbers, as it is the direct cause of 60% to 80% of all accidents.
  In a high risk environment, as is the case in diving, human error is more likely to have catastrophic consequences. A study by William P. Morgan indicates that over half of all divers in the survey had experienced panic underwater at some time during their diving career. These findings were independently corroborated by a survey that suggested 65% of recreational divers have panicked under water. Panic frequently leads to errors in a diver's judgment or performance, and may result in an accident. Human error and panic are considered to be the leading causes of dive accidents and fatalities.
  
  Only 4.46% of the recreational diving fatalities in a 1997 study were attributable to a single contributory cause. The remaining fatalities probably arose as a result of a progressive sequence of events involving two or more procedural errors or equipment failures, and since procedural errors are generally avoidable by a well-trained, intelligent and alert diver, working in an organised structure, and not under excessive stress, it was concluded that the low accident rate in commercial Scuba diving is due to this factor. The study also concluded that it would be impossible to eliminate absolutely all minor contraindications of Scuba diving, as this would result in overwhelming bureaucracy and would bring all diving to a halt. (Full article...)
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  A dive team listens to a safety brief from their dive supervisor

  
  The diving supervisor is the professional diving team member who is directly responsible for the diving operation's safety and the management of any incidents or accidents that may occur during the operation; the supervisor is required to be available at the control point of the diving operation for the diving operation's duration, and to manage the planned dive and any contingencies that may occur. Details of competence, requirements, qualifications, registration and formal appointment differ depending on jurisdiction and relevant codes of practice. Diving supervisors are used in commercial diving, military diving, public safety diving and scientific diving operations.
  
  The control point is the place where the supervisor can best monitor the status of the diver and progress of the dive. For scuba dives this is commonly on deck of the dive boat where there is a good view of the surface above the operational area, or on the shore at a nearby point where the divers can be seen when surfaced. For surface supplied diving, the view of the water is usually still necessary, and a view of the line tenders handling the umbilicals is also required, unless there is live video feed from the divers and two-way audio communications with the tenders. The control position also includes the gas panel and communications panel, so the supervisor can remain as fully informed as practicable of the status of the divers and their life support systems during the dive. For bell diving and saturation diving the situation is more complex and the control position may well be inside a compartment where the communications, control and monitoring equipment for the bell and life-support systems are set up.
  
  In recreational diving the term is used to refer to persons managing a recreational dive, with certification such as Divemaster,
  Dive Control Specialist, Dive Coordinator, etc. (Full article...)
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  A silt out or silt-out is a situation when underwater visibility is rapidly reduced to functional zero by disturbing fine particulate deposits on the bottom or other solid surfaces. This can happen in scuba and surface supplied diving, or in ROV and submersible operations, and is a more serious hazard for scuba diving in penetration situations where the route to the surface may be obscured. (Full article...)

Дайвинг медицина, заболевания и лечение

Указатель дайвинг-медицины, заболеваний и лечения

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  В авиации и подводном плавании альтернобарическое головокружение — это головокружение, возникающее из-за неравномерного давления между ушами из-за того, что одна евстахиева труба менее открыта, чем другая. ( Полная статья... )
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  Freediving blackout, breath-hold blackout, or apnea blackout is a class of hypoxic blackout, a loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold (freedive or dynamic apnea) dive, when the swimmer does not necessarily experience an urgent need to breathe and has no other obvious medical condition that might have caused it. It can be provoked by hyperventilating just before a dive, or as a consequence of the pressure reduction on ascent, or a combination of these. Victims are often established practitioners of breath-hold diving, are fit, strong swimmers and have not experienced problems before. Blackout may also be referred to as a syncope or fainting.
  
  Divers and swimmers who black out or grey out underwater during a dive will usually drown unless rescued and resuscitated within a short time. Freediving blackout has a high fatality rate, and mostly involves males younger than 40 years, but is generally avoidable. Risk cannot be quantified, but is clearly increased by any level of hyperventilation.
  
  Freediving blackout can occur on any dive profile: at constant depth, on an ascent from depth, or at the surface following ascent from depth and may be described by a number of terms depending on the dive profile and depth at which consciousness is lost. Blackout during a shallow dive differs from blackout during ascent from a deep dive in that blackout during ascent is precipitated by depressurisation on ascent from depth while blackout in consistently shallow water is a consequence of hypocapnia following hyperventilation. (Full article...)
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  Latent hypoxia affects the diver on ascent

  
  
  Latent hypoxia is a condition where the oxygen content of the lungs and arterial blood is sufficient to maintain consciousness at a raised ambient pressure, but not when the pressure is reduced to normal atmospheric pressure. It usually occurs when a diver at depth has a lung gas and blood oxygen concentration that is sufficient to support consciousness at the pressure at that depth, but would be insufficient at surface pressure. This problem is associated with freediving blackout and the presence of hypoxic breathing gas mixtures in underwater breathing apparatus, particularly in diving rebreathers.
  
  The term latent hypoxia strictly refers to the situation while the potential victim is at depth, still conscious, and not yet hypoxic, but is also loosely applied to the consequential blackout, which is a form of hypoxic blackout also referred to as blackout of ascent or deep water blackout, though deep water blackout is also used to refer to the final stage of nitrogen narcosis. (Full article...)
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  A recompression chamber is used to treat some diving disorders.

  
  Diving medicine, also called undersea and hyperbaric medicine (UHB), is the diagnosis, treatment and prevention of conditions caused by humans entering the undersea environment. It includes the effects on the body of pressure on gases, the diagnosis and treatment of conditions caused by marine hazards and how relationships of a diver's fitness to dive affect a diver's safety. Diving medical practitioners are also expected to be competent in the examination of divers and potential divers to determine fitness to dive.
  
  Hyperbaric medicine is a corollary field associated with diving, since recompression in a hyperbaric chamber is used as a treatment for two of the most significant diving-related illnesses, decompression sickness and arterial gas embolism.
  
  Diving medicine deals with medical research on issues of diving, the prevention of diving disorders, treatment of diving accidents and diving fitness. The field includes the effect of breathing gases and their contaminants under high pressure on the human body and the relationship between the state of physical and psychological health of the diver and safety.
  
  In diving accidents it is common for multiple disorders to occur together and interact with each other, both causatively and as complications.
  
  Diving medicine is a branch of occupational medicine and sports medicine, and at first aid level, an important part of diver education. (Full article...)
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  Cyanosis of the hand in an elderly person with low oxygen saturation

  
  Hypoxia is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level. Hypoxia may be classified as either generalized, affecting the whole body, or local, affecting a region of the body. Although hypoxia is often a pathological condition, variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise.
  
  Hypoxia differs from hypoxemia and anoxemia, in that hypoxia refers to a state in which oxygen present in a tissue or the whole body is insufficient, whereas hypoxemia and anoxemia refer specifically to states that have low or no oxygen in the blood. Hypoxia in which there is complete absence of oxygen supply is referred to as anoxia.
  
  Hypoxia can be due to external causes, when the breathing gas is hypoxic, or internal causes, such as reduced effectiveness of gas transfer in the lungs, reduced capacity of the blood to carry oxygen, compromised general or local perfusion, or inability of the affected tissues to extract oxygen from, or metabolically process, an adequate supply of oxygen from an adequately oxygenated blood supply.
  
  Generalized hypoxia occurs in healthy people when they ascend to high altitude, where it causes altitude sickness leading to potentially fatal complications: high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE). Hypoxia also occurs in healthy individuals when breathing inappropriate mixtures of gases with a low oxygen content, e.g., while diving underwater, especially when using malfunctioning closed-circuit rebreather systems that control the amount of oxygen in the supplied air. Mild, non-damaging intermittent hypoxia is used intentionally during altitude training to develop an athletic performance adaptation at both the systemic and cellular level.
  
  Hypoxia is a common complication of preterm birth in newborn infants. Because the lungs develop late in pregnancy, premature infants frequently possess underdeveloped lungs. To improve blood oxygenation, infants at risk of hypoxia may be placed inside incubators that provide warmth, humidity, and supplemental oxygen. More serious cases are treated with continuous positive airway pressure (CPAP). (Full article...)
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  During Napoleon Bonaparte's retreat from Russia in the winter of 1812, many troops died from hypothermia.

  
  Hypothermia is defined as a body core temperature below 35.0 °C (95.0 °F) in humans. Symptoms depend on the temperature. In mild hypothermia, there is shivering and mental confusion. In moderate hypothermia, shivering stops and confusion increases. In severe hypothermia, there may be hallucinations and paradoxical undressing, in which a person removes their clothing, as well as an increased risk of the heart stopping.
  
  
  Hypothermia has two main types of causes. It classically occurs from exposure to cold weather and cold water immersion. It may also occur from any condition that decreases heat production or increases heat loss. Commonly, this includes alcohol intoxication but may also include low blood sugar, anorexia and advanced age. Body temperature is usually maintained near a constant level of 36.5–37.5 °C (97.7–99.5 °F) through thermoregulation. Efforts to increase body temperature involve shivering, increased voluntary activity, and putting on warmer clothing. Hypothermia may be diagnosed based on either a person's symptoms in the presence of risk factors or by measuring a person's core temperature.
  
  
  The treatment of mild hypothermia involves warm drinks, warm clothing, and voluntary physical activity. In those with moderate hypothermia, heating blankets and warmed intravenous fluids are recommended. People with moderate or severe hypothermia should be moved gently. In severe hypothermia, extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass may be useful. In those without a pulse, cardiopulmonary resuscitation (CPR) is indicated along with the above measures. Rewarming is typically continued until a person's temperature is greater than 32 °C (90 °F). If there is no improvement at this point or the blood potassium level is greater than 12 millimoles per litre at any time, resuscitation may be discontinued.
  
  
  Hypothermia is the cause of at least 1,500 deaths a year in the United States. It is more common in older people and males. One of the lowest documented body temperatures from which someone with accidental hypothermia has survived is 12.7 °C (54.9 °F) in a 2-year-old boy from Poland named Adam. Survival after more than six hours of CPR has been described. In individuals for whom ECMO or bypass is used, survival is around 50%. Deaths due to hypothermia have played an important role in many wars.
  
  The term is from Greek ῠ̔πο (ypo), meaning "under", and θέρμη (thérmē), meaning "heat". The opposite of hypothermia is hyperthermia, an increased body temperature due to failed thermoregulation. (Full article...)
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  A drawing of people with seasickness from 1841

  
  Motion sickness occurs due to a difference between actual and expected motion. Symptoms commonly include nausea, vomiting, cold sweat, headache, dizziness, tiredness, loss of appetite, and increased salivation. Complications may rarely include dehydration, electrolyte problems, or a lower esophageal tear.
  
  
  The cause of motion sickness is either real or perceived motion. This may include car travel, air travel, sea travel, space travel, or reality simulation. Risk factors include pregnancy, migraines, and Ménière's disease. The diagnosis is based on symptoms.
  
  
  Treatment may include behavioral measures or medications. Behavioral measures include keeping the head still and focusing on the horizon. Three types of medications are useful: antimuscarinics such as scopolamine, H₁ antihistamines such as dimenhydrinate, and amphetamines such as dexamphetamine. Side effects, however, may limit the use of medications. A number of medications used for nausea such as ondansetron are not effective for motion sickness.
  
  
  Nearly all people are affected with sufficient motion and most people will experience motion sickness at least once in their lifetime. Susceptibility, however, is variable, with about one-third of the population being highly susceptible while most other people are affected under extreme conditions. Women are more easily affected than men. Motion sickness has been described since at least the time of Homer (c. eighth century BC). (Full article...)
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  Monitoring the decompression chamber during a simulated medical emergency

  
  
  Hyperbaric treatment schedules or hyperbaric treatment tables, are planned sequences of events in chronological order for hyperbaric pressure exposures specifying the pressure profile over time and the breathing gas to be used during specified periods, for medical treatment. Hyperbaric therapy is based on exposure to pressures greater than normal atmospheric pressure, and in many cases the use of breathing gases with oxygen content greater than that of air.
  
  A large number of hyperbaric treatment schedules are intended primarily for treatment of underwater divers and hyperbaric workers who present symptoms of decompression illness during or after a dive or hyperbaric shift, but hyperbaric oxygen therapy may also be used for other conditions.
  
  Most hyperbaric treatment is done in hyperbaric chambers where environmental hazards can be controlled, but occasionally treatment is done in the field by in-water recompression when a suitable chamber cannot be reached in time. The risks of in-water recompression include maintaining gas supplies for multiple divers and people able to care for a sick patient in the water for an extended period of time. (Full article...)
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  Taravana is a disease often found among Polynesian island natives who habitually dive deep without breathing apparatus many times in close succession, usually for food or pearls. These free-divers may make 40 to 60 dives a day, each of 30 or 40 metres (100 to 140 feet).
  
  Taravana seems to be decompression sickness. The usual symptoms are vertigo, nausea, lethargy, paralysis and death. The word taravana is Tuamotu Polynesian for "to fall crazily".
  
  Taravana is also used to describe someone who is "crazy because of the sea". (Full article...)
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  Divers breathe a mixture of oxygen, helium and nitrogen for deep dives to avoid the effects of narcosis. A cylinder label shows the maximum operating depth and mixture (oxygen/helium).

  
  Narcosis while diving (also known as nitrogen narcosis, inert gas narcosis, raptures of the deep, Martini effect) is a reversible alteration in consciousness that occurs while diving at depth. It is caused by the anesthetic effect of certain gases at high pressure. The Greek word νάρκωσις (narkōsis), "the act of making numb", is derived from νάρκη (narkē), "numbness, torpor", a term used by Homer and Hippocrates. Narcosis produces a state similar to drunkenness (alcohol intoxication), or nitrous oxide inhalation. It can occur during shallow dives, but does not usually become noticeable at depths less than 30 metres (98 ft).
  
  Except for helium and probably neon, all gases that can be breathed have a narcotic effect, although widely varying in degree. The effect is consistently greater for gases with a higher lipid solubility, and although the mechanism of this phenomenon is still not fully clear, there is good evidence that the two properties are mechanistically related. As depth increases, the mental impairment may become hazardous. Divers can learn to cope with some of the effects of narcosis, but it is impossible to develop a tolerance. Narcosis can affect all divers, although susceptibility varies widely among individuals and from dive to dive. The main modes of underwater diving that deal with its prevention and treatment are scuba diving and surface-supplied diving at depths greater than 30 metres (98 ft).
  
  Narcosis may be completely reversed in a few minutes by ascending to a shallower depth, with no long-term effects. Thus narcosis while diving in open water rarely develops into a serious problem as long as the divers are aware of its symptoms, and are able to ascend to manage it. Diving much beyond 40 m (130 ft) is generally considered outside the scope of recreational diving. In order to dive at greater depths, as narcosis and oxygen toxicity become critical risk factors, specialist training is required in the use of various helium-containing gas mixtures such as trimix or heliox. These mixtures prevent narcosis by replacing some or all of the inert fraction of the breathing gas with non-narcotic helium. (Full article...)
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  Monitoring the decompression chamber during a simulated medical emergency

  
  
  Hyperbaric treatment schedules or hyperbaric treatment tables, are planned sequences of events in chronological order for hyperbaric pressure exposures specifying the pressure profile over time and the breathing gas to be used during specified periods, for medical treatment. Hyperbaric therapy is based on exposure to pressures greater than normal atmospheric pressure, and in many cases the use of breathing gases with oxygen content greater than that of air.
  
  A large number of hyperbaric treatment schedules are intended primarily for treatment of underwater divers and hyperbaric workers who present symptoms of decompression illness during or after a dive or hyperbaric shift, but hyperbaric oxygen therapy may also be used for other conditions.
  
  Most hyperbaric treatment is done in hyperbaric chambers where environmental hazards can be controlled, but occasionally treatment is done in the field by in-water recompression when a suitable chamber cannot be reached in time. The risks of in-water recompression include maintaining gas supplies for multiple divers and people able to care for a sick patient in the water for an extended period of time. (Full article...)
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  In 1942–43 the UK Government carried out extensive testing for oxygen toxicity in divers. The chamber is pressurised with air to 3.7 bar. The subject in the centre is breathing 100% oxygen from a mask.

  
  Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen (O
  ₂) at increased partial pressures. Severe cases can result in cell damage and death, with effects most often seen in the central nervous system, lungs, and eyes. Historically, the central nervous system condition was called the Paul Bert effect, and the pulmonary condition the Lorrain Smith effect, after the researchers who pioneered the discoveries and descriptions in the late 19th century. Oxygen toxicity is a concern for underwater divers, those on high concentrations of supplemental oxygen, and those undergoing hyperbaric oxygen therapy.
  
  The result of breathing increased partial pressures of oxygen is hyperoxia, an excess of oxygen in body tissues. The body is affected in different ways depending on the type of exposure. Central nervous system toxicity is caused by short exposure to high partial pressures of oxygen at greater than atmospheric pressure. Pulmonary and ocular toxicity result from longer exposure to increased oxygen levels at normal pressure. Symptoms may include disorientation, breathing problems, and vision changes such as myopia. Prolonged exposure to above-normal oxygen partial pressures, or shorter exposures to very high partial pressures, can cause oxidative damage to cell membranes, collapse of the alveoli in the lungs, retinal detachment, and seizures. Oxygen toxicity is managed by reducing the exposure to increased oxygen levels. Studies show that, in the long term, a robust recovery from most types of oxygen toxicity is possible.
  
  Protocols for avoidance of the effects of hyperoxia exist in fields where oxygen is breathed at higher-than-normal partial pressures, including underwater diving using compressed breathing gases, hyperbaric medicine, neonatal care and human spaceflight. These protocols have resulted in the increasing rarity of seizures due to oxygen toxicity, with pulmonary and ocular damage being largely confined to the problems of managing premature infants.
  
  In recent years, oxygen has become available for recreational use in oxygen bars. The US Food and Drug Administration has warned those who have conditions such as heart or lung disease not to use oxygen bars. Scuba divers use breathing gases containing up to 100% oxygen, and should have specific training in using such gases. (Full article...)
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  Compression arthralgia is pain in the joints caused by exposure to high ambient pressure at a relatively high rate of compression, experienced by underwater divers. Also referred to in the U.S. Navy Diving Manual as compression pains.
  
  Compression arthralgia has been recorded as deep aching pain in the knees, shoulders, fingers, back, hips, neck and ribs. Pain may be sudden and intense in onset and may be accompanied by a feeling of roughness in the joints.
  
  Onset commonly occurs around 60 msw (meters of sea water), and symptoms are variable depending on depth, compression rate and personal susceptibility. Intensity increases with depth and may be aggravated by exercise. Compression arthralgia is generally a problem of deep diving, particularly deep saturation diving, where at sufficient depth even slow compression may produce symptoms. Peter B. Bennett et al. (1974) found that the use of trimix could reduce the symptoms.
  
  Fast compression (descent) may produce symptoms as shallow as 30 msw. Saturation divers generally compress much more slowly, and symptoms are unlikely at less than around 90 msw. At depths beyond 180m even very slow compression may produce symptoms. Spontaneous improvement may occur over time at depth, but this is unpredictable, and pain may persist into decompression. Symptoms may be distinguished from decompression sickness as they are present before starting decompression, and resolve with decreasing pressure, the opposite of decompression sickness. The pain may be sufficiently severe to limit the diver's capacity for work, and may also limit travel rate and depth of downward excursions.
  
  Compression pain can be distinguished from decompression sickness pain because compression pain occurs during descent and resolves during ascent, while decompression sickness occurs during or after ascent. (Full article...)
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  Two United States Navy sailors demonstrate treatment for decompression sickness inside a decompression chamber

  
  Decompression sickness (abbreviated DCS; also called divers' disease, the bends, aerobullosis, and caisson disease) is a medical condition caused by dissolved gases emerging from solution as bubbles inside the body tissues during decompression. DCS most commonly occurs during or soon after a decompression ascent from underwater diving, but can also result from other causes of depressurisation, such as emerging from a caisson, decompression from saturation, flying in an unpressurised aircraft at high altitude, and extravehicular activity from spacecraft. DCS and arterial gas embolism are collectively referred to as decompression illness.
  
  Since bubbles can form in or migrate to any part of the body, DCS can produce many symptoms, and its effects may vary from joint pain and rashes to paralysis and death. DCS often causes air bubbles to settle in major joints like knees or elbows, causing individuals to bend over in excruciating pain, hence its common name, the bends. Individual susceptibility can vary from day to day, and different individuals under the same conditions may be affected differently or not at all. The classification of types of DCS according to symptoms has evolved since its original description in the 19th century. The severity of symptoms varies from barely noticeable to rapidly fatal.
  
  Decompression sickness can occur after an exposure to increased pressure while breathing a gas with a metabolically inert component, then decompressing too fast for it to be harmlessly eliminated through respiration, or by decompression by an upward excursion from a condition of saturation by the inert breathing gas components, or by a combination of these routes. Decompression risk is controlled by the tissue compartment with the highest inert gas concentration, which for decompression from saturation is the slowest tissue to outgas.
  
  The risk of DCS can be managed through proper decompression procedures, and contracting the condition has become uncommon. Its potential severity has driven much research to prevent it, and divers almost universally use decompression schedules or dive computers to limit their exposure and to monitor their ascent speed. If DCS is suspected, it is treated by hyperbaric oxygen therapy in a recompression chamber. Where a chamber is not accessible within a reasonable time frame, in-water recompression may be indicated for a narrow range of presentations, if there are suitably skilled personnel and appropriate equipment available on site. Diagnosis is confirmed by a positive response to the treatment. Early treatment results in a significantly higher chance of successful recovery.
  
  Decompression sickness caused by a decompression from saturation can occur in decompression or upward excursions from saturation diving, ascent to high altitudes, and extravehicular activities in space. Treatment is recompression, and oxygen therapy. (Full article...)
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  High-pressure nervous syndrome (HPNS – also known as high-pressure neurological syndrome) is a neurological and physiological diving disorder which can result when a diver descends below about 500 feet (150 m) using a breathing gas containing helium. The effects experienced, and the severity of those effects, depend on the rate of descent, the depth and the percentage of helium.
  
  "Helium tremors" were described in 1965 by Royal Navy physiologist Peter B. Bennett. Russian scientist G. L. Zal'tsman also reported on helium tremors in his experiments from 1961. However, these reports were not available in the West until 1967.
  
  The term high-pressure nervous syndrome was first used by R. W. Brauer in 1968 to describe the combined symptoms of tremor, electroencephalography (EEG) changes, and somnolence that appeared during a 1,189-foot (362 m) chamber dive in Marseille. (Full article...)

Подводные инструменты и оружие

Указатель подводных инструментов и оружия

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  Подводная винтовка АПС под патрон калибра 5,66 мм.

  
  Подводный автомат АПС ( АПС — «Автомат Подводный Специальный») — подводное огнестрельное оружие, разработанное Советским Союзом в начале 1970-х годов. Принят на вооружение в 1975 году. Изготовлен Тульским оружейным заводом ( Тульский оружейный завод ) в России, экспортируется Рособоронэкспортом .
  
  Под водой обычные пули неточны и имеют очень короткую дальность поражения. АПС стреляет стальным затвором длиной 120 миллиметров (4,7 дюйма) калибра 5,66 мм, специально разработанным для этого оружия. Его магазин вмещает 26 патронов. Ствол АПС не нарезной ; выпущенный снаряд удерживается на траектории за счет гидродинамических эффектов; в результате АПС несколько нетточен при стрельбе из воды.
  
  АПС имеет большую дальность действия и большую проникающую способность, чем ружья . Это полезно в таких ситуациях, как стрельба по водолазу противника через усиленный сухой костюм , защитный шлем (удерживающий воздух или нет), толстые и прочные части дыхательных комплектов и их ремней безопасности , а также пластиковые кожухи и прозрачные чехлы некоторых небольших подводные аппараты .
  
  APS мощнее пистолета, но он громоздче, тяжелее и требует больше времени для прицеливания, особенно если его длинный ствол и большой плоский магазин раскачиваются вбок в воде. ( Полная статья... )
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  Polespear under tension with a cluster head attached.

  
  
  A polespear (hand spear or gidgee) is an underwater tool used in spearfishing, consisting of a pole, a spear tip, and a rubber loop. Polespears are often mistakenly called Hawaiian slings, but the tools differ. A Hawaiian sling is akin to a slingshot or an underwater bow and arrow, since the spear and the propelling device are separate, while a polespear has the sling (rubber loop) attached to the spear. (Full article...)
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  The M1 Underwater Defense Gun, also called the Underwater Defense Gun Mark 1 Mod 0, is an underwater firearm developed by the United States during the Cold War. Similar to other underwater firearms, it fires a special 4.25-inch (108 mm) metal dart as its projectile. (Full article...)
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  Assembled tremie placing concrete underwater

  
  A tremie is a watertight pipe, usually of about 250 mm inside diameter (150 to 300 mm), with a conical hopper at its upper end above the water level. It may have a loose plug or a valve at the bottom end. A tremie is used to pour concrete underwater in a way that avoids washout of cement from the mix due to turbulent water contact with the concrete while it is flowing. This produces a more reliable strength of the product. Common applications include the following.
  

  • Caissons, which are the foundations of bridges, among other things, that span bodies of water.
  • Pilings.
  • Monitoring wells. Builders use tremie methods for materials other than concrete, and for industries other than construction. For example, bentonite slurries for monitoring wells are often emplaced via tremie pipe.

  (Full article...)
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  Airlift dredging

  
  An airlift is device based on a pipe, used in nautical archaeology to suck small objects, sand and mud from the sea bed and to transport the resulting debris upwards and away from its source. It is sometimes called a suction dredge. A water dredge or water eductor may be used for the same purpose.
  
  Typically, the airlift is constructed from a 3-metre to 10 metre long, 10 cm diameter pipe. A controllable compressed air supply vents into the inside, lower end of the pipe (The input end always being the lower end). Compressed air is injected into the pipe in one to three second bursts with an interval long enough to let the resulting bubble to rise to the higher, output end of the pipe. The bubble moves water through the pipe sucking debris from the lower end and depositing it from the upper end of the pipe. Ejected debris can be either cast off (as in simply removing overburden) or collected in a mesh cage for inspection (as more often is the case in nautical archaeology). It is often designed to be hand-operated by a diver.
  
  Airlift pumps are used by water utilities, farmers and others to extract water from deep wells. In such cases the pipes can be 30, 60 or more meters deep underground. Airlift pumps are governed by the physics of two-phase flow. (Full article...)
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  SPP-1M

  
  The SPP-1 underwater pistol was made in the Soviet Union for use by Soviet frogmen as an underwater firearm. It was developed in the late 1960s and accepted for use in 1975. Under water, ordinary-shaped bullets are inaccurate and very short-range. As a result, this pistol fires a round-based 4.5 millimetres (0.18 in) caliber steel dart about 115 millimetres (4.5 in) long, weighing 12.8 grams (0.45 oz), which has longer range and more penetrating power than speargun spears. The complete cartridge is 145 millimetres (5.7 in) long and weighs 17.5 grams (0.62 oz). (Full article...)
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  A limpet mine is a type of naval mine attached to a target by magnets. It is so named because of its superficial similarity to the shape of the limpet, a type of sea snail that clings tightly to rocks or other hard surfaces.
  
  A swimmer or diver may attach the mine, which is usually designed with hollow compartments to give the mine just slight negative buoyancy, making it easier to handle underwater. (Full article...)
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  Speargun

  
  A speargun is a ranged underwater fishing device designed to launch a tethered spear or harpoon to impale fish or other marine animals and targets. Spearguns are used in sport fishing and underwater target shooting. The two basic types are pneumatic and elastic (powered by rubber bands). Spear types come in a number of varieties including threaded, break-away and lined. Floats and buoys are common accessories when targeting larger fish. (Full article...)
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  The 5.45mm ADS rifle

  
  The ADS (Russian: АДС - Автомат Двухсредный Специальный - Special Dual-environment Automatic rifle) is a Russian assault rifle specially made for combat divers. It is of a bullpup layout and is chambered in the 5.45×39mm M74 round. The ADS can adapt a suppressor and optical sights. (Full article...)
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  The APS amphibious rifle, an underwater assault rifle

  
  
  An underwater firearm is a firearm designed for use underwater. Underwater firearms or needleguns usually fire flechettes or spear-like bolts instead of standard bullets. These may be fired by pressurised gas. (Full article...)
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  Powerhead may refer to:
  

  • Powerhead (firearm), a direct-contact, underwater firearm
  • Powerhead (aquarium), a submersible aquarium pump
  • Powerhead (rocket engine), the preburners and turbopumps of a pump-fed rocket engine (excludes the engine combustion chamber and nozzle)
  • Powerhead (pump), the mechanical drive of any one of several non-aquarium pump types; marine propeller powerhead, fountain powerhead, etc.

  (Full article...)
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  The Gyrojet carbine and rifle at the National Firearms Museum

  
  The Gyrojet is a family of unique firearms developed in the 1960s named for the method of gyroscopically stabilizing its projectiles. Rather than inert bullets, Gyrojets fire small rockets called Microjets which have little recoil and do not require a heavy barrel or chamber to resist the pressure of the combustion gases. Velocity on leaving the tube was very low, but increased to around 1,250 feet per second (380 m/s) at 30 feet (9.1 m). The result is a very lightweight and transportable weapon.
  
  Long out of production, today they are a coveted collector's item with prices for even the most common model ranging above $1,000. They are rarely fired; ammunition, when available at all, can cost over $200 per round. (Full article...)
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  Israeli Navy Underwater Missions Unit transfers equipment using lifting-bags

  
  A lifting bag is an item of diving equipment consisting of a robust and air-tight bag with straps, which is used to lift heavy objects underwater by means of the bag's buoyancy. The heavy object can either be moved horizontally underwater by the diver or sent unaccompanied to the surface.
  
  Lift bag appropriate capacity should match the task at hand. If the lift bag is grossly oversized a runaway or otherwise out of control ascent may result. Commercially available lifting bags may incorporate dump valves to allow the operator to control the buoyancy during ascent, but this is a hazardous operation with high risk of entanglement in an uncontrolled lift or sinking. If a single bag is insufficient, multiple bags may be used, and should be distributed to suit the load.
  
  There are also lifting bags used on land as short lift jacks for lifting cars or heavy loads or lifting bags which are used in machines as a type of pneumatic actuator which provides load over a large area. These lifting bags of the AS/CR type are for example used in the brake mechanism of rollercoasters. (Full article...)
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  The ASM-DT Underwater Assault Rifle

  
  The ASM-DT is a Russian prototype folding-stock underwater firearm. It emerged in the 1990s. (Full article...)
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  The Hawaiian sling is a device used in spearfishing. The sling operates much like a bow and arrow does on land, but energy is stored in rubber tubing rather than a wooden or fiberglass bow. (Full article...)

История подводного плавания

Указатель истории подводного плавания

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  Российское правительство взяло на себя обязательство поднять затонувший корабль и вернуть останки экипажа в рамках спасательной операции стоимостью 65 миллионов долларов США. Они заключили контракт с голландскими морскими спасательными компаниями Smit International и Mammoet на поднятие Курска со дна моря. Это стала крупнейшей спасательной операцией такого типа, когда-либо проводившейся. Спасательная операция была чрезвычайно опасной из-за риска радиации от реактора. Учтено только семь из 24 торпед подводной лодки. ( Полная статья... )
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  The timeline of underwater diving technology is a chronological list of notable events in the history of the development of underwater diving equipment. With the partial exception of breath-hold diving, the development of underwater diving capacity, scope, and popularity, has been closely linked to available technology, and the physiological constraints of the underwater environment.
  
  Primary constraints are

  • the provision of breathing gas to allow endurance beyond the limits of a single breath,
  • safely decompressing from high underwater pressure to surface pressure,
  • the ability to see clearly enough to effectively perform the task,
  • and sufficient mobility to get to and from the workplace.

  (Full article...)
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  Brian Andrew Hills, born 19 March 1934 in Cardiff, Wales, died 13 January 2006 in Brisbane, Queensland, was a physiologist who worked on decompression theory.
  
  Early decompression work was done with Hugh LeMessurier's aeromedicine group at the department of Physiology, University of Adelaide. His "thermodynamic decompression model" was one of the first models in which decompression is controlled by the volume of gas bubbles coming out of solution. In this model, pain only DCS is modelled by a single tissue which is diffusion-limited for gas uptake, and bubble-formation during decompression causes "phase equilibration" of partial pressures between dissolved and free gases. The driving mechanism for gas elimination in this tissue is inherent unsaturation, also called partial pressure vacancy or the oxygen window, where oxygen metabolised is replaced by more soluble carbon dioxide. This model was used to explain the effectiveness of the Torres Strait Islands pearl divers' empirically developed decompression schedules, which used deeper decompression stops and less overall decompression time than the current naval decompression schedules. This trend to deeper decompression stops has become a feature of more recent decompression models.
  
  Hills made a significant contribution to the mainstream scientific literature of some 186 articles between 1967 and 2006. The first 15 years of this contribution are mostly related to decompression theory. Other contributions to decompression science include the development of two early decompression computers, a method to detect tissue bubbles using electrical impedance, the use of kangaroo rats as animal models for decompression sickness, theoretical and experimental work on bubble nucleation, inert gas uptake and washout, acclimatisation to decompression sickness, and isobaric counterdiffusion. (Full article...)
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  NOAA drawing of Dr. Bond and the SEALAB habitat. (1960s) Captain George Bond's Discoveries Enable Divers to Stay Below Indefinitely

  
  Captain George Foote Bond (November 14, 1915 – January 3, 1983) was a United States Navy physician who was known as a leader in the field of undersea and hyperbaric medicine and the "Father of Saturation Diving".
  
  While serving as Officer-in-Charge at the Naval Medical Research Laboratory in Groton, Connecticut, he conducted his earliest experiments into saturation diving techniques.
  In 1957, Bond began the Genesis project to prove that humans could in fact withstand prolonged exposure to different breathing gases and increased environmental pressures. Once saturation is achieved, the amount of time needed for decompression depends only on the depth and gases breathed. This was the beginning of saturation diving and the US Navy's Man-in-the-Sea Program.
  
  The first two phases of Project Genesis involved exposing animals to saturation in various breathing gases. In 1962, interest in helium-oxygen atmospheres for crewed space flights made Phase C possible. Phase C involved saturation of three subjects at one atmosphere (surface) in a 21.6% oxygen, 4% nitrogen, and 74.4% helium environment for six days. In phase D experiments at the United States Navy Experimental Diving Unit in 1963, the subjects performed the world's first saturation dive at a depth of 100 feet of seawater (fsw) in a 7% oxygen, 7% nitrogen, and 86% helium environment for 6 days. In phase E trials in 1963 divers were saturated for 12 days at 198 fsw breathing 3.9% oxygen, 6.5% nitrogen and 89.6% helium. A 27-hour linear ascent was made from saturation.
  
  "Papa Topside" Bond initiated and served as the Senior Medical Officer and principal investigator of the US Navy SEALAB program. SEALAB I was lowered off the coast of Bermuda in 1964 to a depth of 192 fsw below the sea's surface. The experiment was halted after 11 days due to an approaching tropical storm. SEALAB I proved that saturation diving in the open ocean was a viable means for expanding our ability to live and work in the sea. The experiment also provided engineering solutions to habitat placement, habitat umbilicals, humidity, and helium speech descrambling. SEALAB II was launched off the coast of California in 1965 to assess the feasibility of utilizing saturation techniques and tools to accomplish a variety of tasks that would be difficult or impossible to accomplish by repeated dives from the surface. In addition to physiological testing, the divers tested new tools, methods of salvage, and an electrically heated drysuit. SEALAB III was placed in water three times as deep to test new salvage techniques and for oceanographic and fishery studies. On February 15, 1969, SEALAB III was lowered to 610 fsw (185 m), off San Clemente Island, California. The habitat soon began to leak and six divers were sent to repair it, but they were unsuccessful. During the second attempt, aquanaut Berry L. Cannon died, and the program came to a halt. (Full article...)
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  Operation Thunderhead was a highly classified combat mission conducted by U.S. Navy SEAL Team One and Underwater Demolition Team 11 (UDT-11) in 1972. The mission was conducted off the coast of North Vietnam during the Vietnam War to rescue two U.S. airmen said to be escaping from a prisoner of war prison in Hanoi. The prisoners, including Air Force Colonel John A. Dramesi were planning to steal a boat and travel down the Red River to the Gulf of Tonkin.
  
  Lieutenant Melvin Spence Dry was killed on the mission. He was the last SEAL lost during the Vietnam War. His father, retired Navy Captain Melvin H. Dry, spent the rest of his life trying to learn the circumstances surrounding his son's death. The details, however, were long shrouded in secrecy. (Full article...)
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  The timeline of underwater diving technology is a chronological list of notable events in the history of the development of underwater diving equipment. With the partial exception of breath-hold diving, the development of underwater diving capacity, scope, and popularity, has been closely linked to available technology, and the physiological constraints of the underwater environment.
  
  Primary constraints are

  • the provision of breathing gas to allow endurance beyond the limits of a single breath,
  • safely decompressing from high underwater pressure to surface pressure,
  • the ability to see clearly enough to effectively perform the task,
  • and sufficient mobility to get to and from the workplace.

  (Full article...)
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  The Raid on Algiers took place on 11 December 1942, in the Algiers harbour. Italian manned torpedoes and commando frogmen from the Decima Flottiglia MAS were brought to Algiers aboard the Perla-class submarine Ambra. The participating commandos were captured after setting limpet mines which sank two Allied ships and damaged two more. (Full article...)
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  Colonel William Paul Fife USAF (Ret) (November 23, 1917 – October 13, 2008) was a United States Air Force officer that first proved the feasibility for U.S. Air Force Security Service airborne Communications Intelligence (COMINT) collection and Fife is considered the "Father of Airborne Intercept". Fife was also a hyperbaric medicine specialist who was known for his pioneering research on pressurized environments ranging from high altitude to underwater habitats. Fife was a Professor Emeritus at Texas A&M University. (Full article...)
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  Captain Albert Richard Behnke Jr. USN (ret.) (August 8, 1903 – January 16, 1992) was an American physician, who was principally responsible for developing the U.S. Naval Medical Research Institute. Behnke separated the symptoms of Arterial Gas Embolism (AGE) from those of decompression sickness and suggested the use of oxygen in recompression therapy.
  
  Behnke is also known as the "modern-day father" of human body composition for his work in developing the hydrodensitometry method of measuring body density, his standard man and woman models as well as a somatogram based on anthropometric measurements. (Full article...)
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  State of the art in the late 1960s - Underwater photographer Odd Henrik Johnsen

  
  
  Vintage scuba is scuba equipment dating from 1975 and earlier, and the practice of diving using such equipment. (Full article...)
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  Captain Charles Wesley Shilling (September 21, 1901 – December 23, 1994) was an American physician who was known as a leader in the field of undersea and hyperbaric medicine, research, and education. Shilling was widely recognized as an expert on deep sea diving, naval medicine, radiation biology, and submarine capabilities. In 1939, he was Senior Medical Officer in the rescue of the submarine U.S.S. Squalus. (Full article...)
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  Olterra at anchor shortly before being broken up at Vado Ligure, 1961

  
  The auxiliary ship Olterra was a 5,000 ton Italian tanker scuttled by her own crew at Algeciras in the Bay of Gibraltar on 10 June 1940, after the entry of Italy in World War II. She was recovered in 1942 by a special unit of the Decima Flottiglia MAS to be used as an undercover base for manned torpedoes in order to attack Allied shipping at Gibraltar. (Full article...)
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  Defenses against swimmer incursions are security methods developed to protect watercraft, ports and installations, and other sensitive resources in or near vulnerable waterways from potential threats or intrusions by swimmers or scuba divers. (Full article...)
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  This is a listing of researchers who have made discoveries or inventions relating to the science and technology of underwater diving.
  Divers who have become notable due to their exploits are not listed here, unless they have published research findings or invented an important item of diving related equipment. For these, see List of underwater divers. (Full article...)
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  Simon Mitchell returns from the 2002 world record dive to the wreck of the SS Kyogle. The dive re-opened the file on the AHS Centaur

  
  
  Simon Mitchell (born 1958) is a New Zealand physician specialising in occupational medicine, hyperbaric medicine and anesthesiology. Trained in medicine, Mitchell was awarded a PhD for his work on neuroprotection from embolic brain injury. Mitchell has also published more than 45 research and review papers in the medical literature. Mitchell is an author and avid technical diver. He also wrote two chapters of the latest edition of Bennett and Elliott's Physiology and Medicine of Diving, is the co-author of the diving textbook Deeper Into Diving with John Lippmann and co-authored the chapter on Diving and Hyperbaric Medicine in Harrison's Principles of Internal Medicine with Michael Bennett. (Full article...)

Обучение, регистрация и сертификация дайверов

Указатель обучения, сертификации, регистрации и стандартов дайверов

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  Уровни образования в области подводного плавания, используемые ISO, PADI, CMAS, SSI и NAUI.

  
  Advanced Open Water Diver (AOWD) — это уровень сертификации по любительскому подводному плаванию , предоставляемый несколькими агентствами по обучению дайверов . Агентства, предлагающие этот уровень обучения под этим названием, включают Профессиональную ассоциацию инструкторов по дайвингу (PADI) и Международные школы подводного плавания (SSI). Другие агентства предлагают аналогичное обучение под разными названиями. Advanced Open Water Diver — это один шаг вперед от сертификации начального уровня начинающего автономного дайвера. Основное различие между сертификатом Open Water Diver (OWD) , эквивалентным автономному дайверу , и AOWD заключается в том, что предел глубины увеличен с 18 до 30 метров (от 60 до 100 футов). Обязательным уровнем сертификации для обучения AOWD является OWD или признанный эквивалент (ISO 24801-2). Сертификационные требования для AOWD включают теоретическое обучение и оценку, практическое обучение и оценку, а также минимальное требование к количеству зарегистрированных погружений, которое варьируется в зависимости от агентства. SSI требует 24 зарегистрированных погружений. PADI требует 5 погружений на курсе, а обязательным условием является OWD, который требует 4 погружений в открытой воде. Дополнительные зарегистрированные погружения не указаны. ( Полная статья... )
  
  
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  The Health and Safety Executive (HSE) is a UK public body responsible for the encouragement, regulation and enforcement of workplace health, safety and welfare, and for research into occupational risks in Great Britain. It is a non-departmental public body of the United Kingdom with its headquarters in Bootle, England. In Northern Ireland, these duties lie with the Health and Safety Executive for Northern Ireland. The HSE was created by the Health and Safety at Work etc. Act 1974, and has since absorbed earlier regulatory bodies such as the Factory Inspectorate and the Railway Inspectorate though the Railway Inspectorate was transferred to the Office of Rail and Road in April 2006. The HSE is sponsored by the Department for Work and Pensions. As part of its work, HSE investigates industrial accidents, small and large, including major incidents such as the explosion and fire at Buncefield in 2005. Though it formerly reported to the Health and Safety Commission, on 1 April 2008, the two bodies merged. (Full article...)
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  The Cave Divers Association of Australia (CDAA) is a cave diving organisation which was formed in September 1973 to represent the interests of recreational scuba divers who dive in water‐filled caves and sinkholes principally in the Lower South East (now called the Limestone Coast) of South Australia (SA) and secondly in other parts of Australia. Its formation occurred after a series of diving fatalities in waterfilled caves and sinkholes in the Mount Gambier region between 1969 and 1973 and in parallel to a Government of South Australia inquiry into these deaths. The CDAA's major achievement has been the dramatic reduction of fatalities via the introduction of a site rating scheme and an associated testing system which was brought in during the mid-1970s. While its major area of operation is in the Limestone Coast region of SA, it administers and supports cave diving activity in other parts of Australia including the Nullarbor Plain and Wellington, New South Wales. (Full article...)
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  Master Scuba Diver (MSD) is a scuba diving certification or recognition level offered by several North American diver training agencies, such as the National Association of Underwater Instructors (NAUI), the Professional Association of Diving Instructors (PADI), Scuba Diving International (SDI), and Scuba Schools International (SSI). Other agencies (e.g., The International Association of Nitrox and Technical Divers) offer similar programs under other names, such as "Elite Diver". Each of these (and other) agencies touts their program at this level as the highest, non-leadership program.
  
  Most organizations have a minimum age requirement of 15 to undertake the Master Scuba Diver course, although some organizations do permit certification of "Junior" Master Scuba Divers. (Full article...)
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  American Nitrox Divers International (or ANDI) was founded by Ed Betts and Dick Rutkowski in 1988.
  
  ANDI has since expanded to include offices in The United Kingdom, Israel, Australia, Sweden, Italy, Germany, The Netherlands, Greece, Japan, Taiwan, Republic of Korea, Republic of Maldives, Republic of Philippines, Latin America, Middle East, with its home office in the United States of America.
  
  "SafeAir" is ANDI's term of art for breathing mixtures with extra oxygen added that are commonly known as nitrox or Enriched Air Nitrox (EAN). (Full article...)
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  The International Diving Educators Association is an American diving training organization that was originally established in 1952 as part of the Florida Skin Divers Association (FSDA).
  
  In the early days, Scuba Instructor training and certification was handled by the FSDA Scuba Training Committee which was also in charge of Standards & Procedures and new diver certifications. By 1976 there were more FSDA instructors outside of Florida than within the state.
  
  In February 1976, the membership voted to expand the Scuba Training Committee to an international certification agency. The name was changed and the International Diving Educators Association (IDEA) was formed. A new name, a new logo, and a new direction lead to a new “IDEA.”.
  In 1979 IDEA was reorganized and incorporated. IDEA made its first international appearance as a member of the Diving Equipment Manufacturers Association (DEMA) in Las Vegas in 1980. IDEA grew into over 30 foreign countries and across the continental United States. In 1996 IDEA became the fourth largest certification agency worldwide.
  
  IDEA is American owned and operated by US military veterans and first responders. In 1987 the majority of certification agencies agreed to form a not-for-profit agency known as the Recreational Scuba Training Council (RSTC). The purpose of the RSTC is to allow member associations a vehicle for developing standards and to monitor quality control for the mutual benefit of the recreational diving industry and the general public.
  
  IDEA, along with the other members of the RSTC, developed the standards for the Entry Level Scuba standards registered and approved by ANSI. IDEA has affiliates operating in Asia and Europe.
  
  IDEA Europe is a member of RSTC Europe. (Full article...)
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  The International Association of Nitrox and Technical Divers (IANTD) is a scuba diving organization concerned with certification and training in recreational diving, technical diving, cave diving, wreck diving, rebreather diving and diver leadership. Originally formed as the International Association of Nitrox Divers in 1985 by Dick Rutkowski it pioneered the introduction of Enriched Air Nitrox diving to the recreational diving community, before its name change in 1992 to reflect the more "technical" diving courses it had begun to teach. The European Association of Technical Divers (EATD) became part of IANTD in 1993. (Full article...)
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  ACUC, American and Canadian Underwater Certifications Inc. is an international recreational diving membership and diver training organization. Formerly known as the Association of Canadian Underwater Councils, it was formed as a not for profit collective of regional dive councils to create a national forum for their common interest and concerns. It soon began developing a training curriculum better suited to the Canadian conditions that many other training agencies neglected. It was later incorporated in 1986 in Canada by Robert Cronkwright. Cronkwright was a National Association of Underwater Instructors (NAUI) instructor from 1969 to 1971. In 1971 he crossed over to the Association of Canadian Underwater Councils and became a Training Director, Secretary/Treasurer and later Vice President of the Association (1972–1984). He was also Training Director for the Ontario Underwater Council (OUC) in the 1970s.
  
  Cronkwright's long-time friend and ACUC Instructor Trainer Evaluator, Juan Rodriguez, purchased shares in the company in the mid-1990s. Since becoming an ACUC Instructor, Rodriguez was instrumental in expanding ACUC's business interests in the global marketplace. In May 2003 Juan Rodriguez became the sole owner and President when Cronkwright retired. Nancy Cronkwright, Cronkwright's daughter, continues as Vice President and Director of the corporation. She has been with the company since its beginning in 1986, and she was Office Manager for the Association of Canadian Underwater Councils (1982–1986). (Full article...)
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  Confédération Mondiale des Activités Subaquatiques (CMAS) is an international federation that represents underwater activities in underwater sport and underwater sciences, and oversees an international system of recreational snorkel and scuba diver training and recognition. It is also known by its English name, the World Underwater Federation, and its Spanish name, Confederación Mundial De Actividades Subacuáticas. Its foundation in Monaco during January 1959 makes it one of the world's oldest underwater diving organisations. (Full article...)
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  The Sub-Aqua Association or SAA is a diver training organization for scubadivers in the United Kingdom. The SAA and other UK-based diving groups have traditionally used a club-based system with unpaid instructors, while other training agencies organise most of their training programs through professional instructors and dive shops. The other major club-based diving organizations in the UK are the British Sub-Aqua Club (BSAC) and the Scottish Sub Aqua Club, and the principal non-club-based organisation is PADI. (Full article...)
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  Dive RAID International (formerly RAID) is a dive training organization which was founded in 2007 to support diver training for the Poseidon Mk VI Discovery Rebreather. It has since extended its scope to include open circuit scuba training and training for both recreational and technical diving sectors as well as snorkeling and freediving. (Full article...)
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  The American Academy of Underwater Sciences (AAUS) is a group of scientific organizations and individual members who conduct scientific and educational activities underwater. It was organized in 1977 and incorporated in the State of California in 1983. (Full article...)

Подводные водолазные организации

Указатель организаций подводного плавания

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  Comhairle Fo-Thuinn ( произносится [ˈkoːɾˠl̠ʲə fˠɔˈhiːnʲ] ; по-ирландски означает «Подводный совет»; CFT ), также известный как Ирландский подводный совет ( IUC ) и торговый как Diving Ireland , является национальным руководящим органом любительского дайвинга и подводных видов спорта в Ирландия. ( Полная статья... )
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  Crest of NACSAC

  
  The Naval Air Command Sub Aqua Club (NACSAC) was an organization within the Royal Navy that oversaw sports and technical diving training activities for naval aviation and fleet units. Today, it has branches at RNAS Culdrose (HMS Seahawk) and RNAS Yeovilton (HMS Heron). Both bases provide training, and club members regularly dive into their local areas on weekends. Diving instruction, from beginner to advanced level, is offered under the auspices of the British Sub-Aqua Club. In 2005, NACSAC was closed down as an organization in favour of the Royal Navy Sub Aqua Club, which is what Lieutenant Graham and CPO Larn had wanted from the outset of NACSAC, which was only given that title since HMS Vernon, the RN Diving School at Portsmouth would not support the idea of sport diving within the service. (Full article...)
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  A cave diver running a reel with guide line into the overhead environment

  
  
  Cave-diving is underwater diving in water-filled caves. It may be done as an extreme sport, a way of exploring flooded caves for scientific investigation, or for the search for and recovery of divers or, as in the 2018 Thai cave rescue, other cave users. The equipment used varies depending on the circumstances, and ranges from breath hold to surface supplied, but almost all cave-diving is done using scuba equipment, often in specialised configurations with redundancies such as sidemount or backmounted twinset. Recreational cave-diving is generally considered to be a type of technical diving due to the lack of a free surface during large parts of the dive, and often involves planned decompression stops. A distinction is made by recreational diver training agencies between cave-diving and cavern-diving, where cavern diving is deemed to be diving in those parts of a cave where the exit to open water can be seen by natural light. An arbitrary distance limit to the open water surface may also be specified.
  
  Equipment, procedures, and the requisite skills have been developed to reduce the risk of becoming lost in a flooded cave, and consequently drowning when the breathing gas supply runs out. The equipment aspect largely involves the provision of an adequate breathing gas supply to cover reasonably foreseeable contingencies, redundant dive lights and other safety critical equipment, and the use of a continuous guideline leading the divers back out of the overhead environment. The skills and procedures include effective management of the equipment, and procedures to recover from foreseeable contingencies and emergencies, both by individual divers, and by the teams that dive together.
  
  In the United Kingdom, cave-diving developed from the locally more common activity of caving. Its origins in the United States are more closely associated with recreational scuba diving. Compared to caving and scuba diving, there are relatively few practitioners of cave-diving. This is due in part to the specialized equipment and skill sets required, and in part because of the high potential risks due to the specific environment.
  
  Despite these risks, water-filled caves attract scuba divers, cavers, and speleologists due to their often unexplored nature, and present divers with a technical diving challenge. Underwater caves have a wide range of physical features, and can contain fauna not found elsewhere. Several organisations dedicated to cave diving safety and exploration exist, and several agencies provide specialised training in the skills and procedures considered necessary for acceptable safety. (Full article...)
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  The Royal Australian Navy School of Underwater Medicine (RANSUM) is an instructor-led training course based at Sydney, Australia. (Full article...)
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  The International Association for Handicapped Divers (or "IAHD") is a non-profit organization with its headquarters in Middenmeer, the Netherlands. The organization was established in 1993, with the aim to promote, develop and conduct programs for the training in scuba diving of people with a disability. From 1993 to date (2008) IAHD have educated and certified over 5500 divers and dive professionals worldwide. As the IAHD is a non-profit foundation, all the people on the board are volunteers. There are also volunteers in regions around the world.
  
  Physical exercise helps people improve their health both physically and mentally. A person with a disability gets these benefits as well as increased social activity by taking up an activity like scuba diving. Being involved with such activities may even result in giving a person with a disability a renewed interest in life and provide positive and lasting benefits.
  
  The risks in training a disabled person in diving are no higher than for able bodied people. Instructors may have to alter some of the techniques and some equipment may also need changing to meet the individual's need. In some cases extra pool or open water training may be needed. In some extreme cases even individual lessons may be needed. IAHD believes that people with a disability should be in a regular class at some point in their training. (Full article...)
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  The Diving Medical Advisory Council (DMAC) is an independent organisation of diving medical specialists, mostly from across Northern Europe which exists to provide expert advice about medical and some safety aspects of commercial diving. The advice is published in the form of guidance documents, which are made available for download.
  
  The committee has also issued position statements on the following subjects:

  • Commercial Diving and Health (October 2006)
  • Health Surveillance of Commercial Divers (April 2008)
  • Exercise Testing in Medical Assessment of Commercial Divers (October 2009)
  • Requirement for Air Diving to 50 msw in Commercial Diver Training (March 2013)
  • Deep Saturation Diving (April 2013)
  • Education and Training in Diving Medicine (November 2014)

  (Full article...)
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  The Australian Underwater Federation (AUF) is the governing body for underwater sports in Australia. (Full article...)
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  DDRC Healthcare is a not-for-profit organization and a registered UK charity (no. 279652) based in Plymouth in the United Kingdom. They offer global services relating to diving medicine.
  
  The organisation employs approximately 60 staff (2023) as regular employees and contracted staff. The organization was established in 1980 at Fort Bovisand in Devon, England - to research the effects of underwater diving on human physiology. (Full article...)
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  The South African Environmental Observation Network (SAEON) is a science network of people, organisations and, most importantly observation platforms, that perform Long-Term Ecological Research (LTER) in South Africa and its surrounding oceans. The SAEON is of global importance as an innovative approach in ecology to understand environmental change and to determine the impact of anthropogenic forces at multiple scales but it is a remarkably complex challenge to statistically discern between ubiquitous natural variability and exogenous forcing. The SAEON constitutes a national government response to the World Summit on Sustainable Development (Earth Summit 2002) and is a component of the GEO (Group on Earth Observations). The SAEON has become the leader in environmental science and observation in South Africa, but has been criticised for taking a long time to establish, a situation which was inevitable in view of SAEON's multiple stakeholder corps. It has also been raised that the cost of replicated experimental treatments across SAEON sites will be high. (Full article...)
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  The Fédération Française d'Études et de Sports Sous-Marins (FFESSM) is a French sports federation specialized in recreational and competition underwater sports, like scuba diving and freediving. It is the main diver training organization in France.
  
  The historical ancestor of the federation was created in 1948 under the name "Federation of societies for underwater fishing and swimming", and merged in 1955 with the "French federation of underwater activities" to become the current organization. It is one of the founding members of the Confédération Mondiale des Activités Subaquatiques (CMAS, World Confederation of Underwater Activities) created in 1959.
  
  It has 140,000 members, 6,000 instructors, in 2,500 clubs. The federation has a delegation from the French Ministry of Sports to organize and develop scuba diving and related activities nationwide. (Full article...)
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  The British Freediving Association (BFA, also known as AIDA-UK) is an organisation established in the United Kingdom during 1999 to promote the safe practice of both competition and recreational freediving. It is the British affiliate of AIDA International. The BFA is the sole body that selects teams for international competitions conducted by AIDA International and ratifies any UK record attempts.
  
  The British Freediving Association organises UK Freediving pool and depth competitions every year. The Great Northern pool competition was hosted by ApneistsUK who have hosted the Pool Championships in 2010, 2011, 2012, 2013 and 2014. The last depth competition was 2012. (Full article...)
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  The Cave Divers Association of Australia (CDAA) is a cave diving organisation which was formed in September 1973 to represent the interests of recreational scuba divers who dive in water‐filled caves and sinkholes principally in the Lower South East (now called the Limestone Coast) of South Australia (SA) and secondly in other parts of Australia. Its formation occurred after a series of diving fatalities in waterfilled caves and sinkholes in the Mount Gambier region between 1969 and 1973 and in parallel to a Government of South Australia inquiry into these deaths. The CDAA's major achievement has been the dramatic reduction of fatalities via the introduction of a site rating scheme and an associated testing system which was brought in during the mid-1970s. While its major area of operation is in the Limestone Coast region of SA, it administers and supports cave diving activity in other parts of Australia including the Nullarbor Plain and Wellington, New South Wales. (Full article...)
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  British Underwater Sports Association (BUSA) is the British affiliate of the Sports Committee of Confédération Mondiale des Activités Subaquatiques (CMAS).
  
  It was created in 1997 to fill the vacancy on the CMAS Sport Committee for the United Kingdom caused by the expulsion of the British Sub-Aqua Club from CMAS in order to ensure ongoing access to international competition offered by CMAS for British underwater sports teams.
  
  Its members include the British Finswimming Association, British Octopush Association and British Spearfishing Association.
  
  Its role is exclusively one of representation of British underwater sports at the international level. It does not have any recognition from the British government or the governments of the four constituent countries of the UK. BUSA members seeking government funding for sporting activities are required to obtain a letter of support from the National Governing Body (NGB) for Sub Aqua in their country. These include the BSAC for the UK and England, Northern Ireland Federation of Sub-Aqua Clubs for Northern Ireland, the Scottish Sub Aqua Club for Scotland and the Welsh Association of Sub Aqua Clubs for Wales. However, in June 2013, UK Sport and Sport England reportedly published their requirements for the acceptance of BUSA as the NGB for underwater sports in the UK. (Full article...)
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  Confédération Mondiale des Activités Subaquatiques (CMAS) is an international federation that represents underwater activities in underwater sport and underwater sciences, and oversees an international system of recreational snorkel and scuba diver training and recognition. It is also known by its English name, the World Underwater Federation, and its Spanish name, Confederación Mundial De Actividades Subacuáticas. Its foundation in Monaco during January 1959 makes it one of the world's oldest underwater diving organisations. (Full article...)

Публикации по подводному дайвингу

Указатель публикаций по подводному дайвингу

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  Последнее погружение: фатальное погружение отца и сына в глубины океана (2000) —научно-популярнаякнига, написаннаядайверомБерни Чоудхури и опубликованная издательствомHarperCollins. В нем документируется фатальное погружение Криса Роуза-старшего и Криса «Крисси» Роуза-младшего, команды отца и сына, которые погибли у побережья Нью-Джерси в 1992 году. Автор является экспертом по дайвингу и был другом Роузов.
  
  Водолазы исследовали немецкую подводную лодку на глубине 230 футов (70 м) у побережья Нью-Джерси. Несмотря на опыт использованиятехническихгазовых смесей для дайвинга, таких как «тримикс» (добавление гелия к азоту и кислороду, содержащимся в воздухе), они ныряли только на сжатом воздухе. Пара намеревалась забратьбортовой журнал капитанау так называемогоU-Who, чтобы «осуществить свою мечту о погружении в славу».
  
  Чоудхури — технический дайвер, который, согласно рецензии писателя Нила Мэтьюза накнигуРоберта Курсона «Shadow Divers» (2004), «был одним из первых, кто адаптировал принципы пещерного дайвинга к глубоководным затонувшим кораблям». Также, по словам Мэтьюза, «его книга документирует, как столкновения философии снаряжения между спелеологами и затонувшими дайверами отражают столкновение дайверских субкультур». ( Полная статья... )
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  The Darkness Beckons (ISBN 0-939748-32-0) is the definitive book on the history of UK cave diving.
  
  It was written by Martyn Farr, a major figure in UK diving at a time when many of the original participants were still alive and available for interview. (Full article...)
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  The NOAA Diving Manual: Diving for Science and Technology is a book originally published by the US Department of Commerce for use as training and operational guidance for National Oceanographic and Atmospheric Administration divers. NOAA also publish a Diving Standards and Safety Manual (NDSSM), which describes the minimum safety standards for their diving operations. Several editions of the diving manual have been published, and several editors and authors have contributed over the years. The book is widely used as a reference work by professional and recreational divers. (Full article...)
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  Goldfinder is a 2001 autobiography of British diver and treasure hunter Keith Jessop. It tells the story of Jessop's life and salvaging such underwater treasures as HMS Edinburgh, one of the greatest deep sea salvage operations and most financially rewarding in history.
  
  One day in April 1981 Jessop's survey ship Dammtor began searching for the wreck of HMS Edinburgh in the Barents Sea in the Arctic Ocean of the coast of Russia. The ship had been sunk in battle in 1942 during World War II while carrying payment for military equipment from Murmansk in Russia to Scotland. His company, called Jessop Marine, won the contract for the salvage rights to the wreck of Edinburgh because his methods, involving complex cutting machinery and divers, were deemed more appropriate for a war grave, compared to the explosives-oriented methods of other companies.
  
  In late April 1981, the survey ship discovered the ship's final resting place at an approximate position of 72.00°N, 35.00°E, at a depth of 245 metres (804 ft) within ten days of the start of the operation. Using specialist camera equipment, Dammtor took detailed film of the wreck, which allowed Jessop and his divers to carefully plan the salvage operation.
  
  Later that year, on 30 August, the dive-support vessel Stephaniturm journeyed to the site, and salvage operations began in earnest. Leading the operation undersea, by mid-September of that year Jessop was able to salvage over $100,000,000 in Russian gold bullion (431 bars) from the wreck out of 465 over several days making him the greatest underwater treasurer in history.
  
  Jessop died on 22 May 2010. (Full article...)
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  Shadow Divers: The True Adventure of Two Americans Who Risked Everything to Solve One of the Last Mysteries of World War II is a 2004 non-fiction book by Robert Kurson recounting of the discovery of a World War II German U-boat 60 miles (97 km) off the coast of New Jersey, United States in 1991, exploration dives, and its eventual identification as U-869 lost on 11 February 1945. (Full article...)
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  The Silent World (subtitle: A story of undersea discovery and adventure, by the first men to swim at record depths with the freedom of fish) is a 1953 book co-authored by Captain Jacques-Yves Cousteau and Frédéric Dumas, and edited by James Dugan. (Full article...)

Распознанный контент

Избранные статьи

• Кронан (корабль)
• Мэри Роуз
• Метаболизм
• Кислородная токсичность
• Военный корабль США Саратога (CV-3)
• Подводное плавание
• Васа (корабль)
• СС Вашингтониан (1913)

Главная страница избранные статьи

• Кронан (корабль)
• Мэри Роуз
• Метаболизм
• Кислородная токсичность
• Подводное плавание
• Васа (корабль)
• СС Вашингтониан (1913)

Избранные списки

• Список признаков и симптомов нарушений дайвинга

Хорошие статьи

• 115 (баржа)
• Военный корабль США «Арканзас» (BB-33)
• Дэвид Аттенборо
• Уильям Биб
• HMSAS Блумфонтейн
• HMS Boadicea (H65)
• Подводная гора Боуи
• Хью Брэднер
• Отравление угарным газом
• Скотт Карпентер
• СС Каюга
• СС Честер А. Конгдон
• Декомпрессионная болезнь
• Декомпрессия (дайвинг)
• Декомпрессионное оборудование
• Практика декомпрессии
• Профиль погружения
• Водолазная связь
• Дайвинг-цилиндр
• Император СС
• Сила
• СМС Гейер
• САС Хорошая Надежда
• История исследований и разработок декомпрессии
• СС Айронсайдс
• СС Джон В. Моран
• Скотт Келли (астронавт)
• PS Кистоун Стэйт
• СС Манасу
• Военный корабль США Монитор
• Азотный наркоз
• Атолл Перл и Гермес
• HMS Пелорус (J291)
• HMS Prince of Wales (53)
• Лени Рифеншталь
• HMS Сафари
• Японский крейсер Сакава
• Подводное плавание с аквалангом
• Соло-дайвинг
• Полк специальной воздушной службы
• Специальная воздушная служба
• Специальный лодочный сервис
• HMS Темза (1885 г.)
• САС Трансвааль
• Немецкая подводная лодка Ю-40 (1938 г.)
• СС Вернон
• Военный корабль США Янси

Бывшие хорошие статьи

• Большой Барьерный риф
• Остров Кадмат
• Липид
• Поверхностное натяжение

В новостных статьях

• Рику Браунинг
• Скотт Карпентер
• Арка Дарвина
• Глубоководный Челленджер
• Джон Линдберг
• Российская подводная лодка Лошарик.
• Пилар Луна
• Затопление концепции MV
• Роб Стюарт (режиссер)
• Спасение пещеры Тхам Луанг

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  На этой картине Джозефа Райта из Дерби « Эксперимент над птицей в воздушном насосе» , 1768 год, изображен эксперимент, первоначально проведенный Робертом Бойлем в 1660 году.

  
  
  Декомпрессия в контексте дайвинга происходит из-за снижения давления окружающей среды , испытываемого дайвером во время всплытия в конце погружения или гипербарического воздействия, и относится как к снижению давления , так и к процессу удаления растворенных инертных газов из тканей во время этого снижения давления.
  
  Когда дайвер погружается в толщу воды, давление окружающей среды повышается. Дыхательный газ подается под тем же давлением, что и окружающая вода, и часть этого газа растворяется в крови и других тканях дайвера. Инертный газ продолжает поступать до тех пор, пока газ, растворенный в водолазе, не придет в состояние равновесия с дыхательным газом в легких водолаза ( см.: « Погружение с насыщением »), или пока водолаз не поднимется в толще воды и не уменьшит давление окружающей среды дыхательного газа до тех пор, пока инертные газы, растворенные в тканях, не достигнут более высокой концентрации, чем равновесное состояние, и не начнут снова диффундировать. Растворенные инертные газы, такие как азот или гелий , могут образовывать пузырьки в крови и тканях дайвера, если парциальное давление растворенных газов в дайвере становится слишком высоким по сравнению с давлением окружающей среды . Эти пузырьки и продукты травм, вызванных ими, могут вызвать повреждение тканей, известное как декомпрессионная болезнь или изгибы . Непосредственная цель контролируемой декомпрессии — избежать развития симптомов образования пузырьков в тканях дайвера, а долгосрочная цель — также избежать осложнений из-за субклинической декомпрессионной травмы.
  
  Известно, что симптомы декомпрессионной болезни обусловлены повреждением, возникающим в результате образования и роста пузырьков инертного газа внутри тканей, а также блокированием артериального кровоснабжения тканей пузырьками газа и другими эмболами , возникающими вследствие образования пузырьков и повреждения тканей. Точные механизмы образования пузырей и причиняемый ими ущерб в течение значительного времени были предметом медицинских исследований, было выдвинуто и проверено несколько гипотез. Таблицы и алгоритмы для прогнозирования результатов графиков декомпрессии для определенных гипербарических воздействий были предложены, протестированы и использованы, и обычно они оказываются полезными, но не совсем надежными. Декомпрессия остается процедурой с некоторым риском, но она уменьшена и обычно считается приемлемой для погружений в хорошо проверенном диапазоне коммерческого, военного и любительского дайвинга.
  
  Первая зарегистрированная экспериментальная работа, связанная с декомпрессией, была проведенаРоберт Бойль , который подвергал экспериментальных животных пониженному давлению окружающей среды с помощью примитивного вакуумного насоса . В самых ранних экспериментах испытуемые умирали от удушья, но в более поздних экспериментах наблюдались признаки того, что позже стало известно как декомпрессионная болезнь. Позже, когда технологические достижения позволили использовать наддув шахт и кессонов для исключения попадания воды, у шахтеров наблюдались симптомы того, что впоследствии стало известно как кессонная болезнь, изгибы и декомпрессионная болезнь. Как только было признано, что симптомы были вызваны пузырьками газа и что рекомпрессия может облегчить симптомы, дальнейшая работа показала, что симптомов можно избежать путем медленной декомпрессии, и впоследствии были разработаны различные теоретические модели для прогнозирования профилей декомпрессии с низким риском. и лечение декомпрессионной болезни. ( Полная статья... )
• Image 2

  
  

  

  Diving cylinders to be filled at a diving air compressor station

  
  A diving cylinder or diving gas cylinder is a gas cylinder used to store and transport high pressure gas used in diving operations. This may be breathing gas used with a scuba set, in which case the cylinder may also be referred to as a scuba cylinder, scuba tank or diving tank. When used for an emergency gas supply for surface supplied diving or scuba, it may be referred to as a bailout cylinder or bailout bottle. It may also be used for surface-supplied diving or as decompression gas . A diving cylinder may also be used to supply inflation gas for a dry suit or buoyancy compensator. Cylinders provide gas to the diver through the demand valve of a diving regulator or the breathing loop of a diving rebreather.
  
  Diving cylinders are usually manufactured from aluminium or steel alloys, and when used on a scuba set are normally fitted with one of two common types of cylinder valve for filling and connection to the regulator. Other accessories such as manifolds, cylinder bands, protective nets and boots and carrying handles may be provided. Various configurations of harness may be used by the diver to carry a cylinder or cylinders while diving, depending on the application. Cylinders used for scuba typically have an internal volume (known as water capacity) of between 3 and 18 litres (0.11 and 0.64 cu ft) and a maximum working pressure rating from 184 to 300 bars (2,670 to 4,350 psi). Cylinders are also available in smaller sizes, such as 0.5, 1.5 and 2 litres, however these are usually used for purposes such as inflation of surface marker buoys, dry suits and buoyancy compensators rather than breathing. Scuba divers may dive with a single cylinder, a pair of similar cylinders, or a main cylinder and a smaller "pony" cylinder, carried on the diver's back or clipped onto the harness at the side. Paired cylinders may be manifolded together or independent. In technical diving, more than two scuba cylinders may be needed.
  
  When pressurised, the gas is compressed up to several hundred times atmospheric pressure. The selection of an appropriate set of diving cylinders for a diving operation is based on the amount of gas required to safely complete the dive. Diving cylinders are most commonly filled with air, but because the main components of air can cause problems when breathed underwater at higher ambient pressure, divers may choose to breathe from cylinders filled with mixtures of gases other than air. Many jurisdictions have regulations that govern the filling, recording of contents, and labelling for diving cylinders. Periodic testing and inspection of diving cylinders is often obligatory to ensure the safety of operators of filling stations. Pressurised diving cylinders are considered dangerous goods for commercial transportation, and regional and international standards for colouring and labelling may also apply. (Full article...)
• Image 3

  
  

  Divers breathe a mixture of oxygen, helium and nitrogen for deep dives to avoid the effects of narcosis. A cylinder label shows the maximum operating depth and mixture (oxygen/helium).

  
  Narcosis while diving (also known as nitrogen narcosis, inert gas narcosis, raptures of the deep, Martini effect) is a reversible alteration in consciousness that occurs while diving at depth. It is caused by the anesthetic effect of certain gases at high pressure. The Greek word νάρκωσις (narkōsis), "the act of making numb", is derived from νάρκη (narkē), "numbness, torpor", a term used by Homer and Hippocrates. Narcosis produces a state similar to drunkenness (alcohol intoxication), or nitrous oxide inhalation. It can occur during shallow dives, but does not usually become noticeable at depths less than 30 metres (98 ft).
  
  Except for helium and probably neon, all gases that can be breathed have a narcotic effect, although widely varying in degree. The effect is consistently greater for gases with a higher lipid solubility, and although the mechanism of this phenomenon is still not fully clear, there is good evidence that the two properties are mechanistically related. As depth increases, the mental impairment may become hazardous. Divers can learn to cope with some of the effects of narcosis, but it is impossible to develop a tolerance. Narcosis can affect all divers, although susceptibility varies widely among individuals and from dive to dive. The main modes of underwater diving that deal with its prevention and treatment are scuba diving and surface-supplied diving at depths greater than 30 metres (98 ft).
  
  Narcosis may be completely reversed in a few minutes by ascending to a shallower depth, with no long-term effects. Thus narcosis while diving in open water rarely develops into a serious problem as long as the divers are aware of its symptoms, and are able to ascend to manage it. Diving much beyond 40 m (130 ft) is generally considered outside the scope of recreational diving. In order to dive at greater depths, as narcosis and oxygen toxicity become critical risk factors, specialist training is required in the use of various helium-containing gas mixtures such as trimix or heliox. These mixtures prevent narcosis by replacing some or all of the inert fraction of the breathing gas with non-narcotic helium. (Full article...)
• Image 4

  
  

  

  Surface supplied diver on diving stage

  
  There are several categories of decompression equipment used to help divers decompress, which is the process required to allow divers to return to the surface safely after spending time underwater at higher ambient pressures.
  
  Decompression obligation for a given dive profile must be calculated and monitored to ensure that the risk of decompression sickness is controlled. Some equipment is specifically for these functions, both during planning before the dive and during the dive. Other equipment is used to mark the underwater position of the diver, as a position reference in low visibility or currents, or to assist the diver's ascent and control the depth.
  
  Decompression may be shortened ("accelerated") by breathing an oxygen-rich "decompression gas" such as a nitrox blend or pure oxygen. The high partial pressure of oxygen in such decompression mixes produces the effect known as the oxygen window. This decompression gas is often carried by scuba divers in side-slung cylinders. Cave divers who can only return by a single route, can leave decompression gas cylinders attached to the guideline ("stage" or "drop cylinders") at the points where they will be used. Surface-supplied divers will have the composition of the breathing gas controlled at the gas panel.
  
  Divers with long decompression obligations may be decompressed inside gas filled hyperbaric chambers in the water or at the surface, and in the extreme case, saturation divers are only decompressed at the end of a project, contract, or tour of duty that may be several weeks long. (Full article...)
• Image 5

  

  Dive profile of an actual dive as recorded by a personal dive computer and displayed on a desktop screen using dive logging software. In this case depth is in metres.

  
  A dive profile is a description of a diver's pressure exposure over time. It may be as simple as just a depth and time pair, as in: "sixty for twenty," (a bottom time of 20 minutes at a depth of 60 feet) or as complex as a second by second graphical representation of depth and time recorded by a personal dive computer. Several common types of dive profile are specifically named, and these may be characteristic of the purpose of the dive. For example, a working dive at a limited location will often follow a constant depth (square) profile, and a recreational dive is likely to follow a multilevel profile, as the divers start deep and work their way up a reef to get the most out of the available breathing gas. The names are usually descriptive of the graphic appearance.
  
  The intended dive profile is useful as a planning tool as an indication of the risks of decompression sickness and oxygen toxicity for the exposure, to calculate a decompression schedule for the dive, and also for estimating the volume of open-circuit breathing gas needed for a planned dive, as these depend in part upon the depth and duration of the dive. A dive profile diagram is conventionally drawn with elapsed time running from left to right and depth increasing down the page.
  
  Many personal dive computers record the instantaneous depth at small time increments during the dive. This data can sometimes be displayed directly on the dive computer or more often downloaded to a personal computer, tablet, or smartphone and displayed in graphic form as a dive profile. (Full article...)
• Image 6

  

  Solo diver surveying a dive site. The bailout cylinder can be seen slung at the diver's left side

  
  
  Solo diving is the practice of self-sufficient underwater diving without a "dive buddy", particularly with reference to scuba diving, but the term is also applied to freediving. Professionally, solo diving has always been an option which depends on operational requirements and risk assessment. Surface supplied diving and atmospheric suit diving are commonly single diver underwater activities but are accompanied by an on-surface support team dedicated to the safety of the diver, including a stand-by diver, and are not considered solo diving in this sense.
  
  Solo freediving has occurred for millennia as evidenced by artifacts dating back to the ancient people of Mesopotamia when people dived to gather food and to collect pearl oysters. It wasn't until the 1950s, with the development of formalised scuba diving training, that recreational solo diving was deemed to be dangerous, particularly for beginners. In an effort to mitigate associated risks, some scuba certification agencies incorporated the practice of buddy diving into their diver training programmes. The true risk of solo diving relative to buddy diving in the same environmental conditions has never been reliably established, and may have been significantly overstated by some organisations, though it is generally recognised that buddy and team diving, when performed as specified in the manuals, will enhance safety to some extent depending on circumstances.
  
  Some divers, typically those with advanced underwater skills, prefer solo diving over buddy diving and acknowledge responsibility for their own safety. One of the more controversial reasons given being the uncertain competence of arbitrarily allocated dive buddies imposed on divers by service providers protected from liability by waivers. Others simply prefer solitude while communing with nature, or find the burden of continuously monitoring another person reduces their enjoyment of the activity, or engage in activities which are incompatible with effective buddy diving practices, and accept the possibility of slightly increased risk, just as others accept the increased risk associated with deeper dives, planned decompression, or penetration under an overhead.
  
  The recreational solo diver uses enhanced procedures, skills and equipment to mitigate the risks associated with not having another competent diver immediately available to assist if something goes wrong. The skills and procedures may be learned through a variety of effective methods to achieve appropriate competence, including formal training programmes with associated assessment and certification. Recreational solo diving, once discouraged by most training agencies, has been accepted since the late 1990s by some agencies that will train and certify experienced divers skilled in self-sufficiency and the use of redundant backup scuba equipment. In most countries there is no legal impediment to solo recreational diving, with or without certification. (Full article...)
• Image 7

  

  The hand signal "OK"

  
  Diver communications are the methods used by divers to communicate with each other or with surface members of the dive team. In professional diving, diver communication is usually between a single working diver and the diving supervisor at the surface control point. This is considered important both for managing the diving work, and as a safety measure for monitoring the condition of the diver. The traditional method of communication was by line signals, but this has been superseded by voice communication, and line signals are now used in emergencies when voice communications have failed. Surface supplied divers often carry a closed circuit video camera on the helmet which allows the surface team to see what the diver is doing and to be involved in inspection tasks. This can also be used to transmit hand signals to the surface if voice communications fails. Underwater slates may be used to write text messages which can be shown to other divers, and there are some dive computers which allow a limited number of pre-programmed text messages to be sent through-water to other divers or surface personnel with compatible equipment.
  
  Communication between divers and between surface personnel and divers is imperfect at best, and non-existent at worst, as a consequence of the physical characteristics of water. This prevents divers from performing at their full potential. Voice communication is the most generally useful format underwater, as visual forms are more affected by visibility, and written communication and signing are relatively slow and restricted by diving equipment.
  
  Recreational divers do not usually have access to voice communication equipment, and it does not generally work with a standard scuba demand valve mouthpiece, so they use other signals. Hand signals are generally used when visibility allows, and there are a range of commonly used signals, with some variations. These signals are often also used by professional divers to communicate with other divers. There is also a range of other special purpose non-verbal signals, mostly used for safety and emergency communications. (Full article...)
• Image 8

  
  

  

  In 1942–43 the UK Government carried out extensive testing for oxygen toxicity in divers. The chamber is pressurised with air to 3.7 bar. The subject in the centre is breathing 100% oxygen from a mask.

  
  Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen (O
  ₂) at increased partial pressures. Severe cases can result in cell damage and death, with effects most often seen in the central nervous system, lungs, and eyes. Historically, the central nervous system condition was called the Paul Bert effect, and the pulmonary condition the Lorrain Smith effect, after the researchers who pioneered the discoveries and descriptions in the late 19th century. Oxygen toxicity is a concern for underwater divers, those on high concentrations of supplemental oxygen, and those undergoing hyperbaric oxygen therapy.
  
  The result of breathing increased partial pressures of oxygen is hyperoxia, an excess of oxygen in body tissues. The body is affected in different ways depending on the type of exposure. Central nervous system toxicity is caused by short exposure to high partial pressures of oxygen at greater than atmospheric pressure. Pulmonary and ocular toxicity result from longer exposure to increased oxygen levels at normal pressure. Symptoms may include disorientation, breathing problems, and vision changes such as myopia. Prolonged exposure to above-normal oxygen partial pressures, or shorter exposures to very high partial pressures, can cause oxidative damage to cell membranes, collapse of the alveoli in the lungs, retinal detachment, and seizures. Oxygen toxicity is managed by reducing the exposure to increased oxygen levels. Studies show that, in the long term, a robust recovery from most types of oxygen toxicity is possible.
  
  Protocols for avoidance of the effects of hyperoxia exist in fields where oxygen is breathed at higher-than-normal partial pressures, including underwater diving using compressed breathing gases, hyperbaric medicine, neonatal care and human spaceflight. These protocols have resulted in the increasing rarity of seizures due to oxygen toxicity, with pulmonary and ocular damage being largely confined to the problems of managing premature infants.
  
  In recent years, oxygen has become available for recreational use in oxygen bars. The US Food and Drug Administration has warned those who have conditions such as heart or lung disease not to use oxygen bars. Scuba divers use breathing gases containing up to 100% oxygen, and should have specific training in using such gases. (Full article...)
• Image 9

  
  

  

  3-D depiction of Bowie Seamount

  
  Bowie Seamount, or SG̱aan Ḵinghlas ("Supernatural One Looking Outward") in the Haida language, is a large submarine volcano in the northeastern Pacific Ocean, located 180 km (110 mi) west of Haida Gwaii, British Columbia, Canada. The seamount is also known as Bowie Bank. The English name for the feature is after William Bowie of the United States Coast and Geodetic Survey.
  
  The volcano has a flat-topped summit rising about 3,000 m (10,000 ft) above the seabed, to 24 m (79 ft) below sea level. The seamount lies at the southern end of a long underwater volcanic mountain range called the Pratt-Welker or Kodiak-Bowie Seamount chain, stretching from the Aleutian Trench in the north almost to Haida Gwaii in the south.
  
  Bowie Seamount lies on the Pacific Plate, a large segment of the Earth's surface which moves in a northwestern direction under the Pacific Ocean. It is adjacent to two other submarine volcanoes; Hodgkins Seamount on its northern flank and Graham Seamount on its eastern flank. (Full article...)
• Image 10

  

  A recompression chamber is used to treat some diving disorders and for training divers to recognise the symptoms.

  
  
  Diving disorders are medical conditions specifically arising from underwater diving. The signs and symptoms of these may present during a dive, on surfacing, or up to several hours after a dive.
  
  The principal conditions are decompression illness (which covers decompression sickness and arterial gas embolism), nitrogen narcosis, high pressure nervous syndrome, oxygen toxicity, and pulmonary barotrauma (burst lung). Although some of these may occur in other settings, they are of particular concern during diving activities.
  
  The disorders are caused by breathing gas at the high pressures encountered at depth, and divers will often breathe a gas mixture different from air to mitigate these effects. Nitrox, which contains more oxygen and less nitrogen, is commonly used as a breathing gas to reduce the risk of decompression sickness at recreational depths (up to about 40 metres (130 ft)). Helium may be added to reduce the amount of nitrogen and oxygen in the gas mixture when diving deeper, to reduce the effects of narcosis and to avoid the risk of oxygen toxicity. This is complicated at depths beyond about 150 metres (500 ft), because a helium–oxygen mixture (heliox) then causes high pressure nervous syndrome. More exotic mixtures such as hydreliox, a hydrogen–helium–oxygen mixture, are used at extreme depths to counteract this. (Full article...)
• Image 11

  
  

  

  Two United States Navy sailors demonstrate treatment for decompression sickness inside a decompression chamber

  
  Decompression sickness (abbreviated DCS; also called divers' disease, the bends, aerobullosis, and caisson disease) is a medical condition caused by dissolved gases emerging from solution as bubbles inside the body tissues during decompression. DCS most commonly occurs during or soon after a decompression ascent from underwater diving, but can also result from other causes of depressurisation, such as emerging from a caisson, decompression from saturation, flying in an unpressurised aircraft at high altitude, and extravehicular activity from spacecraft. DCS and arterial gas embolism are collectively referred to as decompression illness.
  
  Since bubbles can form in or migrate to any part of the body, DCS can produce many symptoms, and its effects may vary from joint pain and rashes to paralysis and death. DCS often causes air bubbles to settle in major joints like knees or elbows, causing individuals to bend over in excruciating pain, hence its common name, the bends. Individual susceptibility can vary from day to day, and different individuals under the same conditions may be affected differently or not at all. The classification of types of DCS according to symptoms has evolved since its original description in the 19th century. The severity of symptoms varies from barely noticeable to rapidly fatal.
  
  Decompression sickness can occur after an exposure to increased pressure while breathing a gas with a metabolically inert component, then decompressing too fast for it to be harmlessly eliminated through respiration, or by decompression by an upward excursion from a condition of saturation by the inert breathing gas components, or by a combination of these routes. Decompression risk is controlled by the tissue compartment with the highest inert gas concentration, which for decompression from saturation is the slowest tissue to outgas.
  
  The risk of DCS can be managed through proper decompression procedures, and contracting the condition has become uncommon. Its potential severity has driven much research to prevent it, and divers almost universally use decompression schedules or dive computers to limit their exposure and to monitor their ascent speed. If DCS is suspected, it is treated by hyperbaric oxygen therapy in a recompression chamber. Where a chamber is not accessible within a reasonable time frame, in-water recompression may be indicated for a narrow range of presentations, if there are suitably skilled personnel and appropriate equipment available on site. Diagnosis is confirmed by a positive response to the treatment. Early treatment results in a significantly higher chance of successful recovery.
  
  Decompression sickness caused by a decompression from saturation can occur in decompression or upward excursions from saturation diving, ascent to high altitudes, and extravehicular activities in space. Treatment is recompression, and oxygen therapy. (Full article...)
• Image 12

  
  

  

  Cap badge of the Special Boat Service

  
  The Special Boat Service (SBS) is the special forces unit of the United Kingdom's Royal Navy. The SBS can trace its origins back to the Second World War when the Army Special Boat Section was formed in 1940. After the Second World War, the Royal Navy formed special forces with several name changes—Special Boat Company was adopted in 1951 and re-designated as the Special Boat Squadron in 1974—until on 28 July 1987 when the unit was renamed as the Special Boat Service after assuming responsibility for maritime counter-terrorism. Most of the operations conducted by the SBS are highly classified, and are rarely commented on by the British government or the Ministry of Defence, owing to their sensitive nature.
  
  The Special Boat Service is the maritime special forces unit of the United Kingdom Special Forces and is described as the sister unit of the British Army 22 Special Air Service Regiment (22 SAS), with both under the operational control of the Director Special Forces. In October 2001, full command of the SBS was transferred from the Commandant General Royal Marines to the Commander-in-Chief Fleet. On 18 November 2003, the SBS were given their own cap badge with the motto "By Strength and Guile". SBS operators are mostly recruited from the Royal Marines Commandos. (Full article...)
• Image 13

  

  Divers decompressing in the water at the end of a dive

  
  The decompression of a diver is the reduction in ambient pressure experienced during ascent from depth. It is also the process of elimination of dissolved inert gases from the diver's body which accumulate during ascent, largely during pauses in the ascent known as decompression stops, and after surfacing, until the gas concentrations reach equilibrium. Divers breathing gas at ambient pressure need to ascend at a rate determined by their exposure to pressure and the breathing gas in use. A diver who only breathes gas at atmospheric pressure when free-diving or snorkelling will not usually need to decompress, Divers using an atmospheric diving suit do not need to decompress as they are never exposed to high ambient pressure.
  
  
  When a diver descends in the water, the hydrostatic pressure, and therefore the ambient pressure, rises. Because breathing gas is supplied at ambient pressure, some of this gas dissolves into the diver's blood and is transferred by the blood to other tissues. Inert gas such as nitrogen or helium continues to be taken up until the gas dissolved in the diver is in a state of equilibrium with the breathing gas in the diver's lungs, at which point the diver is saturated for that depth and breathing mixture, or the depth, and therefore the pressure, is changed, or the partial pressures of the gases are changed by modifying the breathing gas mixture. During ascent, the ambient pressure is reduced, and at some stage the inert gases dissolved in any given tissue will be at a higher concentration than the equilibrium state and start to diffuse out again. If the pressure reduction is sufficient, excess gas may form bubbles, which may lead to decompression sickness, a possibly debilitating or life-threatening condition. It is essential that divers manage their decompression to avoid excessive bubble formation and decompression sickness. A mismanaged decompression usually results from reducing the ambient pressure too quickly for the amount of gas in solution to be eliminated safely. These bubbles may block arterial blood supply to tissues or directly cause tissue damage. If the decompression is effective, the asymptomatic venous microbubbles present after most dives are eliminated from the diver's body in the alveolar capillary beds of the lungs. If they are not given enough time, or more bubbles are created than can be eliminated safely, the bubbles grow in size and number causing the symptoms and injuries of decompression sickness. The immediate goal of controlled decompression is to avoid development of symptoms of bubble formation in the tissues of the diver, and the long-term goal is to avoid complications due to sub-clinical decompression injury.
  
  
  The mechanisms of bubble formation and the damage bubbles cause has been the subject of medical research for a considerable time and several hypotheses have been advanced and tested. Tables and algorithms for predicting the outcome of decompression schedules for specified hyperbaric exposures have been proposed, tested and used, and in many cases, superseded. Although constantly refined and generally considered acceptably reliable, the actual outcome for any individual diver remains slightly unpredictable. Although decompression retains some risk, this is now generally considered acceptable for dives within the well tested range of normal recreational and professional diving. Nevertheless, currently popular decompression procedures advise a 'safety stop' additional to any stops required by the algorithm, usually of about three to five minutes at 3 to 6 metres (10 to 20 ft), particularly 1 on an otherwise continuous no-stop ascent.
  
  
  Decompression may be continuous or staged. A staged decompression ascent is interrupted by decompression stops at calculated depth intervals, but the entire ascent is actually part of the decompression and the ascent rate is critical to harmless elimination of inert gas. A no-decompression dive, or more accurately, a dive with no-stop decompression, relies on limiting the ascent rate for avoidance of excessive bubble formation in the fastest tissues. The elapsed time at surface pressure immediately after a dive is also an important part of decompression and can be thought of as the last decompression stop of a dive. It can take up to 24 hours for the body to return to its normal atmospheric levels of inert gas saturation after a dive. When time is spent on the surface between dives this is known as the "surface interval" and is considered when calculating decompression requirements for the subsequent dive.
  
  
  Efficient decompression requires the diver to ascend fast enough to establish as high a decompression gradient, in as many tissues, as safely possible, without provoking the development of symptomatic bubbles. This is facilitated by the highest acceptably safe oxygen partial pressure in the breathing gas, and avoiding gas changes that could cause counterdiffusion bubble formation or growth. The development of schedules that are both safe and efficient has been complicated by the large number of variables and uncertainties, including personal variation in response under varying environmental conditions and workload. (Full article...)

body:not(.skin-minerva) .mw-parser-output .ifmobile>.mobile{display:none}body.skin-minerva .mw-parser-output .ifmobile>.nomobile{display:inherit;display:initial}Slideshow of selected imagesGallery of selected images

• 
  Image 1Водолазы с надводного снабжения едут по сцене к подводному рабочему месту
• 
  Image 2Подошва в ластах соответствует немецкому стандарту DIN 7876:1980 (из «Очерка подводного дайвинга »).
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  Image 3Маски для дайвинга российского и украинского производства, соответствующие ГОСТ 20568:1975 (из «Очерка подводного плавания ») .
• 
  Image 4Ассортимент трубок 1970-х годов, изготовленных в соответствии с британским стандартом BS 4532:1969 (из «Очерка подводного дайвинга »).

Случайно выбранная цитата

Дайвинг – прекрасное хобби, и было бы неправильно препятствовать этому, но дайверы должны нести ответственность перед собой и другими.

-  Коронер Найджел Медоуз, Предупреждение о курсах дайвинга «Предупреждение о курсах дайвинга». BBC News, Великобритания, Англия. 8 августа 2006 г. Проверено 1 июля 2018 г.

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Тематические области

• Словарь терминологии подводного плавания
• Схема подводного плавания
• Указатель подводного плавания
• Индекс подводных дайверов
• Указатель мест для любительского дайвинга

Связанные проекты

Этот портал находится в рамках WikiProject Underwater Diving , предметного сотрудничества по подводному дайвингу, и WikiProject Portals , сотрудничества по проектированию, разработке и обслуживанию порталов.

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Связанные порталы

Викимедиа

Следующие дочерние проекты Фонда Викимедиа предоставляют дополнительную информацию по этому вопросу:

• Commons
  Бесплатный медиа-репозиторий

• Wikibooks
  Бесплатные учебники и пособия

• Викиданные
  Бесплатная база знаний

• Викиновости
  Новости бесплатного контента

• Wikiquote
  Сборник цитат

• Wikisource
  Библиотека бесплатного контента

• Викиверситет
  Бесплатные инструменты обучения

• Wikivoyage
  Бесплатный путеводитель

• Викисловарь
  , словарь и тезаурус

• Что такое порталы ?
• Список порталов
• Подстраницы портала:Подводное плавание

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