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Портал:Подводное плавание


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Подводное плавание

Для подводного плавания под лед требуются регуляторы, совместимые с холодной водой.
Для подводного плавания под лед требуются регуляторы, совместимые с холодной водой.


Определение темы
Область действия портала

Тематика данного портала охватывает технологии, поддерживающие дайвинг, физиологические и медицинские аспекты дайвинга, навыки и процедуры дайвинга, а также обучение и регистрацию дайверов, подводную деятельность, которая в той или иной степени зависит от дайвинга, экономические, коммерческие, безопасные и правовые аспекты дайвинга, биографические данные известных дайверов, изобретателей и производителей оборудования для дайвинга и исследователей различных аспектов дайвинга.

Введение в подводное плавание
Два водолаза в легких шлемах стоят спина к спине на подводной платформе, держась за перила. На фото также видно судно поддержки над поверхностью на заднем плане.
Водолазы, доставленные с поверхности, едут на платформе к подводному рабочему месту

Подводное плавание , как вид человеческой деятельности, представляет собой практику погружения под поверхность воды для взаимодействия с окружающей средой. Его также часто называют дайвингом , неоднозначным термином с несколькими возможными значениями в зависимости от контекста. Погружение в воду и воздействие высокого давления окружающей среды оказывают физиологические эффекты, которые ограничивают глубину и продолжительность возможных погружений под давлением окружающей среды . Люди физиологически и анатомически не приспособлены к условиям окружающей среды для дайвинга, и было разработано различное оборудование для увеличения глубины и продолжительности погружений человека, а также для выполнения различных видов работ.

При погружении под давлением окружающей среды дайвер напрямую подвергается давлению окружающей воды. Дайвер под давлением окружающей среды может погружаться на задержке дыхания (фридайвинг ) или использовать дыхательный аппарат для подводного плавания или погружения с подачей воздуха с поверхности , а техника погружения с насыщением снижает риск декомпрессионной болезни (ДКБ) после длительных глубоких погружений. Атмосферные водолазные костюмы (АДС) могут использоваться для изоляции дайвера от высокого давления окружающей среды. Экипируемые подводные аппараты могут расширять диапазон глубин до полной глубины океана , 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 , обучением , типами оборудования и дыхательных газов, используемых в зависимости от режима, глубины и цели погружения, оно остается относительно опасным занятием. Профессиональный дайвинг обычно регулируется законодательством о безопасности и гигиене труда, в то время как любительский дайвинг может быть полностью нерегулируемым. Дайвинг-деятельность ограничена максимальной глубиной около 40 метров (130 футов) для любительского подводного плавания, 530 метров (1740 футов) для коммерческого насыщенного погружения и 610 метров (2000 футов) при ношении атмосферных костюмов. Дайвинг также ограничен условиями, которые не являются чрезмерно опасными, хотя уровень приемлемого риска может варьироваться, и могут произойти смертельные случаи.

Рекреационный дайвинг (иногда называемый спортивным дайвингом или подводным плаванием) — популярный вид досуга. Технический дайвинг — это форма рекреационного дайвинга в более сложных условиях. Профессиональный дайвинг (коммерческий дайвинг, дайвинг в исследовательских целях или ради финансовой выгоды) подразумевает работу под водой. Дайвинг для общественной безопасности — это подводная работа, выполняемая правоохранительными органами, пожарными и подводными поисково-спасательными группами. Военный дайвинг включает боевые погружения, разминирование и содержание судов .Глубоководное погружение — это подводное погружение, обычно с оборудованием, поставляемым с поверхности, и часто относится к использованиюстандартного водолазного костюмас традиционным медным шлемом.с каской— это любая форма погружения сошлемом, включая стандартный медный шлем и другие формысвободно-проточногоилегкого шлема по требованию. История погружения с задержкой дыхания восходит, по крайней мере, к классическим временам, и есть свидетельства доисторическойохоты и сбораморепродуктов, которые могли включать подводное плавание. Технические достижения, позволяющие подавать дайверу дыхательный газ под водой при давлении окружающей среды, появились недавно, и автономные дыхательные системы разрабатывались ускоренными темпами послеВторой мировой войны. ( Полная статья... )

Как пользоваться этим порталом
  • Найти контент в Википедии можно несколькими способами.

    Если у вас есть полезная строка поиска, поиск Google будет весьма эффективным.

    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.

    Навигационное поле в нижней части страниц, имеющих отношение к проекту, содержит ссылки на перечисленные статьи. (В настоящее время недоступно на мобильных устройствах).

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

    • Обзор подводного плавания представляет собой иерархический список всех статей, но он может быть не всегда актуальным.
    • Индекс подводного дайвинга — это алфавитный список статей и перенаправлений на разделы статей, представляющих общие темы, связанные с дайвингом (также не всегда актуальные). Он имеет подиндексы для некоторых связанных групп статей, таких как:
    • Глоссарий терминологии подводного плавания — это алфавитный список терминов, обычно используемых в дайвинге, и их значений в этом контексте. Полезная краткая справка. Определение часто содержит ссылку на подробную основную статью или раздел статьи о термине. 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 перечислять все статьи, вероятно, в другой иерархической структуре, нежели та, что используется для навигационного поля и списка контуров. Иногда система категорий может быть более подходящей для поиска информации. Она также полезна для обслуживания Википедии и отслеживания связанности статей.

    Если у вас неограниченное время и нет особой цели, вы можете спуститься в кроличью нору – прочитайте статью корня темы Подводное плавание и нажмите на любую ссылку, которая покажется вам интересной. Читайте, пока не найдете другую интересную ссылку и нажмите на нее, в противном случае нажмите стрелку браузера, чтобы вернуться назад, и продолжайте. Остановитесь, когда реальность вторгнется или вам станет скучно, вы устанете, захотите пить или вспыхнет пожар.

    Ни одна из этих систем не идеальна и не завершена. Если вы нашли ошибку или упущение, дайте нам знать или исправьте, если знаете как. Это краудсорсинговый проект — вы можете быть одним из толпы.
Обновить с новыми вариантами ниже (очистить)

Режимы погружения

Указатель режимов погружения
  • Два водолаза в легких шлемах стоят спина к спине на подводной платформе, держась за перила. На фото также видно судно поддержки над поверхностью на заднем плане.
    Водолазы, доставленные с поверхности, едут на платформе к подводному рабочему месту


    Подводное плавание , как вид человеческой деятельности, представляет собой практику погружения под поверхность воды для взаимодействия с окружающей средой. Его также часто называют дайвингом , неоднозначным термином с несколькими возможными значениями в зависимости от контекста.
    Погружение в воду и воздействие высокого давления окружающей среды оказывают физиологические эффекты, которые ограничивают глубину и продолжительность возможных погружений под давлением окружающей среды . Люди физиологически и анатомически не приспособлены к условиям окружающей среды для погружений, и было разработано различное оборудование для увеличения глубины и продолжительности погружений человека и обеспечения различных типов работ.

    При погружениях под давлением окружающей среды дайвер напрямую подвергается давлению окружающей воды. Дайвер под давлением окружающей среды может погружаться на задержке дыхания ( фридайвинг ) или использовать дыхательный аппарат для подводного плавания или погружения с подачей воздуха с поверхности , а техника погружения с насыщением снижает риск декомпрессионной болезни (ДКБ) после длительных глубоких погружений. Атмосферные водолазные костюмы (АДС) могут использоваться для изоляции дайвера от высокого давления окружающей среды. Подводные аппараты с экипажеммогут расширить диапазон глубин до полной глубины океана , 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 , обучением , типами оборудования и дыхательными газами, используемыми в зависимости от режима, глубины и цели погружения, оно остается относительно опасным занятием. Профессиональный дайвинг обычно регулируется законодательством о безопасности и гигиене труда, в то время как любительский дайвинг может быть полностью нерегулируемым.
    Дайвинг-деятельность ограничена максимальной глубиной около 40 метров (130 футов) для любительского подводного плавания, 530 метров (1740 футов) для коммерческого насыщенного погружения и 610 метров (2000 футов) при ношении атмосферных костюмов. Дайвинг также ограничен условиями, которые не являются чрезмерно опасными, хотя уровень приемлемого риска может варьироваться, и могут произойти смертельные случаи.

    Любительский дайвинг (иногда называемый спортивным дайвингом или подводным плаванием) является популярным видом досуга. Технический дайвинг — это вид любительского дайвинга в более сложных условиях. Профессиональный дайвинг (коммерческий дайвинг, дайвинг в исследовательских целях или ради финансовой выгоды) подразумевает работу под водой. Дайвинг для общественной безопасности — это подводная работа, выполняемая правоохранительными органами, пожарными иПодводные поисково-спасательные группы. Военные водолазные работы включают боевые водолазные работы, водолазные работы по разминированию и судоходству .
    Глубоководное погружение — это подводное погружение, обычно с оборудованием, поставляемым с поверхности, и часто относится к использованиюстандартного водолазного костюмас традиционным медным шлемом.с каской— это любая форма погружения сошлемом, включая стандартный медный шлем и другие формысвободно-проточногоилегкого шлема по требованию.
    История погружения с задержкой дыхания восходит, по крайней мере, к классическим временам, и есть свидетельства доисторическойохоты и сбораморепродуктов, которые могли включать подводное плавание. Технические достижения, позволяющие подавать дайверу дыхательный газ под водой при давлении окружающей среды, появились недавно, и автономные дыхательные системы разрабатывались ускоренными темпами послеВторой мировой войны. ( Полная статья... )
  • 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...)
  • Two divers wearing lightweight demand helmets stand back-to-back on an underwater platform holding on to the railings. The photo also shows the support vessel above the surface in the background.
    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 to full ocean depth, 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...)
  • 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...)
  • 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 acronym 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 at ambient pressure 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...)

  • Atmospheric diving suit

    An atmospheric diving suit (ADS), or single atmosphere diving suit is a small one-person articulated submersible which resembles a suit of armour, with elaborate pressure joints to allow articulation while maintaining an internal pressure of one atmosphere. An ADS can enable diving at depths of up to 2,300 feet (700 m) for many hours by eliminating the majority of significant physiological dangers associated with deep diving. The occupant of an ADS does not need to decompress, and there is no need for special breathing gas mixtures, so there is little danger of decompression sickness or nitrogen narcosis when the ADS is functioning properly. An ADS can permit less skilled swimmers to complete deep dives, albeit at the expense of dexterity.

    Atmospheric diving suits in current use include the Newtsuit, Exosuit, Hardsuit and the WASP, all of which are self-contained hard suits that incorporate propulsion units. The Hardsuit is constructed from cast aluminum (forged aluminum in a version constructed for the US Navy for submarine rescue); the upper hull is made from cast aluminum, while the bottom dome is machined aluminum. The WASP is of glass-reinforced plastic (GRP) body tube construction. (Full article...)
  • 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...)
  • 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...)
  • 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...)
  • 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 acronym 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 at ambient pressure 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...)
  • 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 potentially fatal 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...)
  • 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...)
  • 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...)
  • 2nd Reconnaissance Battalion combat diver training with the Dräger LAR V rebreather


    Rebreather diving is underwater diving using diving rebreathers, a class of underwater breathing apparatus which recirculate the breathing gas exhaled by the diver after replacing the oxygen used and removing the carbon dioxide metabolic product. Rebreather diving is practiced by recreational, military and scientific divers in applications where it has advantages over open circuit scuba, and surface supply of breathing gas is impracticable. The main advantages of rebreather diving are extended gas endurance, low noise levels, and lack of bubbles.

    Rebreathers are generally used for scuba applications, but are also occasionally used for bailout systems for surface-supplied diving. Gas reclaim systems used for deep heliox diving use similar technology to rebreathers, as do saturation diving life-support systems, but in these applications the gas recycling equipment is not carried by the diver. Atmospheric diving suits also carry rebreather technology to recycle breathing gas as part of the life-support system, but this article covers the procedures of ambient pressure diving using rebreathers carried by the diver.

    Rebreathers are generally more complex to use than open circuit scuba, and have more potential points of failure, so acceptably safe use requires a greater level of skill, attention and situational awareness, which is usually derived from understanding the systems, diligent maintenance and overlearning the practical skills of operation and fault recovery. Fault tolerant design can make a rebreather less likely to fail in a way that immediately endangers the user, and reduces the task loading on the diver which in turn may lower the risk of operator error. (Full article...)

Водолазное и вспомогательное оборудование

Индекс водолазного и вспомогательного оборудования

  • Ныряльщик в прозрачной силиконовой маске для дайвинга

    Маска для дайвинга (также полумаска , дайвинг-маска или акваланг ) — это элемент водолазного снаряжения , который позволяет дайверам , включая аквалангистов , фридайверов и любителей снорклинга , четко видеть под водой . Водолазы, снабжаемые водой, обычно используют полнолицевую маску или водолазный шлем , но в некоторых системах может использоваться полумаска. Когда человеческий глаз находится в прямом контакте с водой, а не с воздухом , его обычной средой, свет, попадающий в глаз, преломляется под другим углом, и глаз не может сфокусировать свет на сетчатке. Предоставляя воздушное пространство перед глазами, глаз может фокусироваться почти нормально. Форма воздушного пространства в маске немного влияет на способность фокусироваться. Корректирующие линзы могут быть установлены на внутренней поверхности смотрового окна или контактные линзы могут носиться внутри маски, чтобы обеспечить нормальное зрение для людей с дефектами фокусировки.

    Когда дайвер спускается, давление окружающей среды повышается, и становится необходимым выровнять давление внутри маски с внешним давлением окружающей среды, чтобы избежать баротравмы, известной как сдавливание маски . Это делается путем пропуска достаточного количества воздуха через нос в маску, чтобы уменьшить разницу давления, что требует включения носа в воздушное пространство маски. Выравнивание во время подъема происходит автоматически, поскольку избыточный воздух внутри маски легко просачивается через уплотнение.

    Доступен широкий диапазон форм смотровых окон и внутренних объемов, и каждая конструкция, как правило, лучше подходит для некоторых форм лица, чем для других. Хорошая удобная посадка и надежное уплотнение по краям резиновой юбки важны для правильной работы маски. Национальные и международные стандарты, касающиеся масок для дайвинга, обеспечивают средства обеспечения их надлежащего качества. ( Полная статья... )

  • 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...)
  • 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...)

  • 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. Hot water suits are actively heated wetsuits. (Full article...)
  • One type of nitrox cylinder identification label


    Nitrox refers to any gas mixture composed (excepting trace gases) of nitrogen and oxygen that contains less than 78% nitrogen. In the usual application, underwater diving, nitrox is normally distinguished from air and handled differently. The most common use of nitrox mixtures containing oxygen in higher proportions than atmospheric air is in scuba diving, where the reduced partial pressure of nitrogen is advantageous in reducing nitrogen uptake in the body's tissues, thereby extending the practicable underwater dive time by reducing the decompression requirement, or reducing the risk of decompression sickness (also known as the bends). The two most common recreational diving nitrox mixes are 32% and 36% oxygen, which have maximum operating depths of about 110 feet (34 meters) and 95 feet (29 meters respectively.

    Nitrox is used to a lesser extent in surface-supplied diving, as these advantages are reduced by the more complex logistical requirements for nitrox compared to the use of simple low-pressure compressors for breathing gas supply. Nitrox can also be used in hyperbaric treatment of decompression illness, usually at pressures where pure oxygen would be hazardous. Nitrox is not a safer gas than compressed air in all respects; although its use can reduce the risk of decompression sickness, it increases the risks of oxygen toxicity and fire.

    Though not generally referred to as nitrox, an oxygen-enriched air mixture is routinely provided at normal surface ambient pressure as oxygen therapy to patients with compromised respiration and circulation. (Full article...)
  • 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...)

  • 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...)

  • 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 or underwater diving regulator is a pressure regulator that controls the pressure of breathing gas for underwater 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, or to the outside of the hyperbaric chamber, 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...)

  • 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...)

  • 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 re-breather.

    Diving cylinders are usually manufactured from aluminum 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 pressurized, 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 labeling for diving cylinders. Periodic testing and inspection of diving cylinders is often obligatory to ensure the safety of operators of filling stations. Pressurized diving cylinders are considered dangerous goods for commercial transportation, and regional and international standards for colouring and labeling may also apply. (Full article...)

  • 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...)

  • 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...)

  • Surface supplied commercial diving equipment on display at a trade show

    Diving equipment, or underwater 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...)
  • A pair of demand valves fitted to a scuba regulator

    In underwater diving, an alternative air source, or more generally alternative breathing gas source, is a secondary supply of air or other breathing gas for use by the diver in an emergency. Examples include an auxiliary demand valve, a pony bottle and bailout bottle.

    An alternative air source may be fully redundant (completely independent of any part of the main air supply system) or non-redundant, if it can be compromised by any failure of the main air supply. From the diver's point of view, air supplied by a buddy or rescue diver is fully redundant, as it is unaffected by the diver's own air supply in any way, but a second regulator on a double cylinder valve or a secondary demand valve (octopus) is not redundant to the diver carrying it, as it is attached to his or her main air supply. Decompression gas can be considered an alternative gas supply only when the risk of breathing it at the current depth is acceptable.

    Effective use of any alternate air source requires competence in the associated skill set. The procedures for receiving air from another diver or from one's own equipment are most effective and least likely to result in a life-threatening incident if well trained to the extent that they do not distract the diver from other essential matters. A major difference from buddy breathing is that the diver using a redundant alternative air source need not alternate breathing with the donor, which can be a substantial advantage in many circumstances. There is a further significant advantage when the alternate air source is carried by the diver using it, in that it is not necessary to locate the buddy before it is available, but this comes at the cost of extra equipment. (Full article...)
  • 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...)

Процедуры погружения

Указатель процедур погружения
  • Аквалангист-любитель

    Подводное плавание с аквалангом — этовид подводного плавания , при котором дайверы используют дыхательное оборудование , которое полностью независимо от подачи дыхательного газа на поверхность, и поэтому имеет ограниченную, но переменную выносливость. Название « акваланг» является аббревиатурой от « Автономный подводный дыхательный аппарат » и было придумано Кристианом Дж. Ламбертсеном в патенте, поданном в 1952 году. Аквалангисты носят с собой собственный источник дыхательного газа , обычно сжатый воздух , что обеспечивает им большую независимость и подвижность, чем дайверы, использующие подводную подачу , и больше времени под водой, чем фридайверы. Хотя использование сжатого воздуха является обычным явлением, газовая смесь с более высоким содержанием кислорода, известная как обогащенный воздух или нитрокс , стала популярной из-за сниженного потребления азота во время длительных или повторяющихся погружений. Кроме того, дыхательный газ, разбавленный гелием, может использоваться для уменьшения эффектов азотного наркоза во время более глубоких погружений.

    Системы подводного плавания с открытым циклом выпускают дыхательный газ в окружающую среду при выдохе и состоят из одного или нескольких баллонов для дайвинга, содержащих дыхательный газ под высоким давлением, который подается дайверу при давлении окружающей среды через регулятор для дайвинга . Они могут включать в себя дополнительные баллоны для расширения диапазона, декомпрессионный газ или аварийный дыхательный газ . Системы подводного плавания с ребризером замкнутого или полузамкнутого циклапозволяют рециркулировать выдыхаемые газы. Объем используемого газа уменьшен по сравнению с открытым циклом, поэтому для эквивалентной продолжительности погружения можно использовать меньший цилиндр или цилиндры. Ребризеры увеличивают время, проведенное под водой, по сравнению с открытым циклом при том же потреблении метаболического газа; они производят меньше пузырьков и меньше шума, чем акваланг открытого цикла, что делает их привлекательными для тайных военных водолазов, чтобы избежать обнаружения, научных водолазов, чтобы не беспокоить морских животных, и водолазов СМИ, чтобы избежать помех от пузырьков.

    Подводное плавание с аквалангом может быть любительским или профессиональным занятием в ряде приложений, включая научные, военные и общественные роли безопасности, но большинство коммерческих погружений используют водолазное снаряжение, поставляемое с поверхности, когда это осуществимо. Водолазы, участвующие в тайных операциях вооруженных сил, могут называться водолазами , боевыми водолазами или атакующими пловцами.

    Водолаз в основном перемещается под водой с помощью ласт, прикрепленных к ногам, но внешнее движение может обеспечиватьсядайверское транспортное средство для передвижения или сани, вытаскиваемые с поверхности. Другое оборудование, необходимое для подводного плавания, включает маску для улучшения подводного зрения, защиту от воздействия с помощью водолазного костюма , балластные грузы для преодоления избыточной плавучести, оборудование для контроля плавучести и оборудование, связанное с конкретными обстоятельствами и целью погружения, которое может включать трубку при плавании на поверхности, режущий инструмент для управления запутыванием, фонари , подводный компьютер для контроля состояния декомпрессии и сигнальные устройства . Аквалангисты обучаются процедурам и навыкам , соответствующим их уровню сертификации, инструкторами по дайвингу, входящими в организации по сертификации дайверов , которые выдают эти сертификаты. К ним относятся стандартные рабочие процедуры по использованию оборудования и устранению общих опасностей подводной среды , а также аварийные процедуры для самопомощи и помощи аналогично оснащенному дайверу, испытывающему проблемы. Большинство учебных организаций требуют минимального уровня физической подготовки и здоровья , но для некоторых приложений может быть целесообразен более высокий уровень физической подготовки. ( Полная статья... )
  • 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...)
  • A diver touches his first finger tip to his thumb tip while extending his other fingers
    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...)
  • A decompression dive may require the use of more than one gas mixture

    Scuba gas planning is the aspect of dive planning and of gas management which deals with the calculation or estimation of the amounts and mixtures of gases to be used for a planned dive. It may assume that the dive profile, including decompression, is known, but the process may be iterative, involving changes to the dive profile as a consequence of the gas requirement calculation, or changes to the gas mixtures chosen. Use of calculated reserves based on planned dive profile and estimated gas consumption rates rather than an arbitrary pressure is sometimes referred to as rock bottom gas management. The purpose of gas planning is to ensure that for all reasonably foreseeable contingencies, the divers of a team have sufficient breathing gas to safely return to a place where more breathing gas is available. In almost all cases this will be the surface.

    Gas planning includes the following aspects:
    • Choice of breathing gases
    • Choice of scuba configuration
    • Estimation of gas required for the planned dive, including bottom gas, travel gas, and decompression gases, as appropriate to the profile.
    • Estimation of gas quantities for reasonably foreseeable contingencies. Under stress it is likely that a diver will increase breathing rate and decrease swimming speed. Both of these lead to a higher gas consumption during an emergency exit or ascent.
    • Choice of cylinders to carry the required gases. Each cylinder volume and working pressure must be sufficient to contain the required quantity of gas.
    • Calculation of the pressures for each of the gases in each of the cylinders to provide the required quantities.
    • Specifying the critical pressures of relevant gas mixtures for appropriate stages (waypoints) of the planned dive profile (gas matching).


    Gas planning is one of the stages of scuba gas management. The other stages include:
    • Knowledge of personal and team members' gas consumption rates under varying conditions
      • basic consumption at the surface for variations in workload
      • variation in consumption due to depth variation
      • variation in consumption due to dive conditions and personal physical and mental condition
    • Monitoring the contents of the cylinders during a dive
    • Awareness of the critical pressures and using them to manage the dive
    • Efficient use of the available gas during the planned dive and during an emergency
    • Limiting the risk of equipment malfunctions that could cause a loss of breathing gas


    The term "rock bottom gas planning" is used for the method of gas planning based on a planned dive profile where a reasonably accurate estimate of the depths, times, and level of activity is available, so the calculations for gas mixtures and the appropriate quantities of each mixture are known well enough to make fairly rigorous calculations useful. Simpler, easier, and fairly arbitrary rules of thumb are commonly used for dives which do not require long decompression stops. These methods are often adequate for low risk dives, but relying on them for more complex dive plans can put divers at significantly greater risk if they are unaware of the limitations of each method and apply them inappropriately. (Full article...)
  • 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...)

  • 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...)
  • 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 potentially fatal 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...)
  • The instructor monitors a trainee practicing diving skills.

    Scuba skills are skills required to dive safely using self-contained underwater breathing apparatus, known as a scuba set. Most of these skills are relevant to both open-circuit scuba and rebreather scuba, and many also apply to surface-supplied diving. Some scuba skills, which are critical to divers' safety, may require more practice than standard recreational training provides to achieve reliable competence.

    Some skills are generally accepted by recreational diver certification agencies as basic and necessary in order to dive without direct supervision. Others are more advanced, although some diver certification and accreditation organizations may require these to endorse entry-level competence. Instructors assess divers on these skills during basic and advanced training. Divers are expected to remain competent at their level of certification, either by practice or through refresher courses. Some certification organizations recommend refresher training if a diver has a lapse of more than six to twelve months without a dive.

    Skill categories include selection, functional testing, preparation and transport of scuba equipment, dive planning, preparation for a dive, kitting up for the dive, water entry, descent, breathing underwater, monitoring the dive profile (depth, time, and decompression status), personal breathing gas management, situational awareness, communicating with the dive team, buoyancy and trim control, mobility in the water, ascent, emergency and rescue procedures, exit from the water, removal of equipment after the dive, cleaning and preparation of equipment for storage and recording the dive, within the scope of the diver's certification. (Full article...)
  • 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...)
  • A Navy buddy diver team checking their gauges together


    Buddy diving is the use of the buddy system by scuba divers and freedivers. 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...)
  • 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...)
  • 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...)
  • Air, oxygen and helium partial pressure gas blending system

    Gas blending for scuba diving (or gas mixing) is the filling of diving cylinders with non-air breathing gases such as nitrox, trimix and heliox. Use of these gases is generally intended to improve overall safety of the planned dive, by reducing the risk of decompression sickness and/or nitrogen narcosis, and may improve ease of breathing.

    Filling cylinders with a mixture of gases has dangers for both the filler and the diver. During filling there is a risk of fire due to use of oxygen and a risk of explosion due to the use of high-pressure gases. The composition of the mix must be safe for the depth and duration of the planned dive. If the concentration of oxygen is too lean the diver may lose consciousness due to hypoxia and if it is too rich the diver may suffer oxygen toxicity. The concentration of inert gases, such as nitrogen and helium, are planned and checked to avoid nitrogen narcosis and decompression sickness.

    Methods used include batch mixing by partial pressure or by mass fraction, and continuous blending processes. Completed blends are analysed for composition for the safety of the user. Gas blenders may be required by legislation to prove competence if filling for other persons. (Full article...)
  • A group of divers seen from below. Two are holding onto the anchor cable as an aid to depth control during a decompression stop.
    Divers using the anchor cable as an aid to depth control during a decompression stop during ascent.


    To prevent or minimize decompression sickness, divers must properly plan and monitor decompression. Divers follow a decompression model to safely allow the release of excess inert gases dissolved in their body tissues, which accumulated as a result of breathing at ambient pressures greater than surface atmospheric pressure. Decompression models take into account variables such as depth and time of dive, breathing gasses, altitude, and equipment to develop appropriate procedures for safe ascent.

    Decompression may be continuous or staged, where the ascent is interrupted by stops at regular depth intervals, but the entire ascent is part of the decompression, and ascent rate can be critical to harmless elimination of inert gas. What is commonly known as no-decompression diving, or more accurately no-stop decompression, relies on limiting ascent rate for avoidance of excessive bubble formation. Staged decompression may include deep stops depending on the theoretical model used for calculating the ascent schedule. Omission of decompression theoretically required for a dive profile exposes the diver to significantly higher risk of symptomatic decompression sickness, and in severe cases, serious injury or death. The risk is related to the severity of exposure and the level of supersaturation of tissues in the diver. Procedures for emergency management of omitted decompression and symptomatic decompression sickness have been published. These procedures are generally effective, but vary in effectiveness from case to case.

    The procedures used for decompression depend on the mode of diving, the available equipment, the site and environment, and the actual dive profile. Standardized procedures have been developed which provide an acceptable level of risk in the circumstances for which they are appropriate. Different sets of procedures are used by commercial, military, scientific and recreational divers, though there is considerable overlap where similar equipment is used, and some concepts are common to all decompression procedures. In particular, all types of surface oriented diving benefited significantly from the acceptance of personal dive computers in the 1990s, which facilitated decompression practice and allowed more complex dive profiles at acceptable levels of risk. (Full article...)
  • 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...)

Наука дайвинга

Индекс науки о подводном плавании
  • Аквалангист с бифокальными линзами, установленными на маске


    Подводное зрение — это способность видеть объекты под водой , и на это существенно влияет несколько факторов. Под водой объекты менее заметны из-за более низкого уровня естественного освещения, вызванного быстрым затуханием света с расстоянием, пройденным через воду. Они также размываются из-за рассеивания света между объектом и наблюдателем, что также приводит к снижению контрастности. Эти эффекты зависят от длины волны света, цвета и мутности воды. Глаз позвоночных обычно оптимизирован либо для подводного зрения, либо для воздушного зрения, как в случае с человеческим глазом. Острота зрения оптимизированного для воздуха глаза серьезно ухудшается из-за разницы в показателе преломления между воздухом и водой при погружении в прямой контакт. Предоставление воздушного пространства между роговицей и водой может компенсировать это, но имеет побочный эффект искажения масштаба и расстояния. Дайвер учится компенсировать эти искажения. Искусственное освещение эффективно для улучшения освещения на близком расстоянии.

    Стереоскопическая острота , способность оценивать относительные расстояния различных объектов, значительно снижается под водой, и на это влияет поле зрения. Узкое поле зрения, вызванное маленьким смотровым окном в шлеме, приводит к значительному снижению стереоостроты и связанной с этим потере координации рук и глаз. На очень близком расстоянии в чистой воде расстояние недооценивается в соответствии с увеличением из-за рефракции через плоскую линзу маски, но на больших расстояниях - больше, чем досягаемость руки, расстояние имеет тенденцию переоцениваться в степени, зависящей от мутности. Как относительное, так и абсолютное восприятие глубины снижается под водой. Потеря контраста приводит к переоценке, а эффекты увеличения объясняют недооценку на близком расстоянии. Дайверы могут в значительной степени адаптироваться к этим эффектам со временем и с практикой.

    Световые лучи изгибаются, когда они перемещаются из одной среды в другую; величина изгиба определяется показателями преломления двух сред. Если одна среда имеет определенную изогнутую форму, она функционирует как линза . Роговица , жидкость и хрусталик глаза вместе образуют линзу, которая фокусирует изображение на сетчатке . Глаз большинства наземных животных приспособлен для зрения в воздухе. Однако вода имеет примерно такой же показатель преломления, как и роговица (оба около 1,33), что эффективно устраняет фокусирующие свойства роговицы. При погружении в воду вместо фокусировки изображения на сетчатке, они фокусируются за сетчаткой, что приводит к чрезвычайно размытому изображению из-за гиперметропии. Этого в значительной степени можно избежать, если между водой и роговицей оставить воздушное пространство, удерживаемое внутри маски или шлема.

    Вода ослабляет свет из-за поглощения, и когда свет проходит через воду, цвет избирательно поглощается водой. На поглощение цвета также влияет мутность воды и растворенного материала. Вода преимущественно поглощает красный свет и в меньшей степени желтый, зеленый и фиолетовый свет, поэтому цвет, который меньше всего поглощается водой, — это синий свет. Твердые частицы и растворенные материалы могут поглощать разные частоты, и это повлияет на цвет на глубине, что приводит к таким результатам, как типичный зеленый цвет во многих прибрежных водах и темный красно-коричневый цвет многих пресноводных рек и озер из-за растворенного органического вещества.

    Видимость — это термин, который обычно предсказывает способность некоторого человека, животного или прибора оптически обнаруживать объект в данной среде и может быть выражен как мера расстояния, на котором можно различить объект или свет. Факторы, влияющие на видимость, включают освещенность, длину светового пути, частицы, вызывающие рассеивание, растворенные пигменты, поглощающие определенные цвета, а также градиенты солености и температуры, которые влияют на показатель преломления. Видимость можно измерить в любом произвольном направлении и для различных цветных целей, но горизонтальная видимость черной цели уменьшает переменные и соответствует требованиям к прямолинейному и надежному параметру для подводной видимости. Имеются приборы для полевых оценок видимости с поверхности, которые могут информировать команду дайверов о возможных осложнениях. ( Полная статья... )
  • 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...)

  • 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...)
  • 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...)
  • 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...)
  • Example of a dissolved solid (left)

    In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.

    The extent of the solubility of a substance in a specific solvent is generally measured as the concentration of the solute in a saturated solution, one in which no more solute can be dissolved. At this point, the two substances are said to be at the solubility equilibrium. For some solutes and solvents, there may be no such limit, in which case the two substances are said to be "miscible in all proportions" (or just "miscible").

    The solute can be a solid, a liquid, or a gas, while the solvent is usually solid or liquid. Both may be pure substances, or may themselves be solutions. Gases are always miscible in all proportions, except in very extreme situations, and a solid or liquid can be "dissolved" in a gas only by passing into the gaseous state first.

    The solubility mainly depends on the composition of solute and solvent (including their pH and the presence of other dissolved substances) as well as on temperature and pressure. The dependency can often be explained in terms of interactions between the particles (atoms, molecules, or ions) of the two substances, and of thermodynamic concepts such as enthalpy and entropy.

    Under certain conditions, the concentration of the solute can exceed its usual solubility limit. The result is a supersaturated solution, which is metastable and will rapidly exclude the excess solute if a suitable nucleation site appears.

    The concept of solubility does not apply when there is an irreversible chemical reaction between the two substances, such as the reaction of calcium hydroxide with hydrochloric acid; even though one might say, informally, that one "dissolved" the other. The solubility is also not the same as the rate of solution, which is how fast a solid solute dissolves in a liquid solvent. This property depends on many other variables, such as the physical form of the two substances and the manner and intensity of mixing.

    The concept and measure of solubility are extremely important in many sciences besides chemistry, such as geology, biology, physics, and oceanography, as well as in engineering, medicine, agriculture, and even in non-technical activities like painting, cleaning, cooking, and brewing. Most chemical reactions of scientific, industrial, or practical interest only happen after the reagents have been dissolved in a suitable solvent. Water is by far the most common such solvent.

    The term "soluble" is sometimes used for materials that can form colloidal suspensions of very fine solid particles in a liquid. The quantitative solubility of such substances is generally not well-defined, however. (Full article...)
  • Dead space is the volume of air that is inhaled that does not take part in the gas exchange, because it either remains in the conducting airways or reaches alveoli that are not perfused or poorly perfused. It means that not all the air in each breath is available for the exchange of oxygen and carbon dioxide. Mammals breathe in and out of their lungs, wasting that part of the inhalation which remains in the conducting airways where no gas exchange can occur. (Full article...)
  • 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...)

  • 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...)
  • 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...)
  • 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...)
  • 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...)
  • Signs explaining how to escape from a rip current, posted at Mission Beach, San Diego, California

    A rip current (or just 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 as of 2022.

    A rip current is not the same thing as undertow, although some people use that 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...)
  • 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...)
  • In diving and decompression, the oxygen window is the difference between the partial pressure of oxygen (PO2) in arterial blood and the PO2 in body tissues. It is caused by metabolic consumption of oxygen. (Full article...)

Профессиональное дайвинг

Индекс профессионального дайвинга
  • Инструкторы и ученики дайверов отрабатывают навыки подводного плавания в закрытой воде


    Инструктор по дайвингу — это человек, который обучает и, как правило, также оценивает компетентность дайверов. Сюда входят фридайверы , дайверы-любители , включая подкатегорию технических дайверов , и профессиональные дайверы , которые включают военных , коммерческих , общественных и научных дайверов .

    В зависимости от юрисдикции, как правило, будут опубликованы конкретные кодексы практики и руководства по обучению, компетентности и регистрации инструкторов по дайвингу, поскольку они обязаны заботиться о своих клиентах и ​​работают в среде с внутренними опасностями, которые могут быть незнакомы неспециалисту. Обучение и оценка, как правило, следуют стандарту обучения дайверов и могут использовать руководство по обучению дайверов в качестве исходного материала.

    Инструкторы по любительскому дайвингу обычно являются зарегистрированными членами одного или нескольких агентств по сертификации любительских дайверов и, как правило, регистрируются для обучения и оценки дайверов в соответствии с указанными стандартами сертификации. Первоначально эти стандарты были на усмотрение каждого агентства по обучению и сертификации, но теперь существуют межведомственные и международные стандарты, гарантирующие, что основные навыки, необходимые для приемлемой безопасности, включены в качестве минимального стандарта как для инструкторов, так и для любительских дайверов. Военные инструкторы по дайвингу, как правило, являются военнослужащими, для которых они готовят персонал. Коммерческие инструкторы по дайвингу могут быть обязаны зарегистрироваться в назначенных национальным правительством организациях и соответствовать определенным стандартам обучения и оценки, но в некоторых частях мира могут быть и другие требования. ( Полная статья... )
  • NAUI Nitrox diver certification card


    A Diving certification or C-card is a document (usually a wallet sized plastic card) recognizing that an individual or organization authorized to do so, "certifies" that the bearer has completed a course of training as required by the agency issuing the card. This is assumed to represent a defined level of skill and knowledge in underwater diving. Divers carry a qualification record or certification card which may be required to prove their qualifications when booking a dive trip, hiring scuba equipment, having diving cylinders filled, or in the case of professional divers, seeking employment.

    Although recreational certifications are issued by numerous different diver training agencies, the entry-level grade is not always equivalent. Different agencies will have different entry-level requirements as well as different higher-level grades, but all are claimed to allow a diver to develop their skills and knowledge in achievable steps.

    In contradistinction, a diver's logbook, or the electronic equivalent, is primarily evidence of range of diving experience. (Full article...)
  • 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...)
  • ROKS Lee Jongmoo (SS-066) and USS Columbus (SSN-762) off the coast of Hawaii; a United States Navy P-3 Orion can be seen observing them nearby.

    Underwater warfare, also known as undersea warfare or subsurface warfare, is naval warfare involving underwater vehicle or combat operations conducted underwater. It is one of the four operational areas of naval warfare, the others being surface warfare, aerial warfare, and information warfare. Underwater warfare includes: (Full article...)
  • 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...)
  • 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...)
  • 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...)
  • 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...)
  • Underwater demolition is the deliberate destruction or neutralization of man-made or natural underwater obstacles, both for military and civilian purposes. (Full article...)
  • 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, behaviors 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 harbors) 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 harbors); 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...)
  • Diver wearing a diving helmet is sanding a repair patch on a submarine
    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...)
  • Nesconset fire department scuba rescue team on training exercise


    Public safety diving is underwater diving conducted as part of law enforcement and fire/rescue. Public safety divers differ from recreational, scientific and commercial divers who can generally plan the date, time, and location of a dive, and dive only if the conditions are conducive to the task. Public safety divers respond to emergencies 24 hours a day, 7 days a week, and may be required to dive in the middle of the night, during inclement weather, in zero visibility "black water," or in waters polluted by chemicals and biohazards. (Full article...)
  • 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...)
  • A divemaster (DM) is a role that includes organising and leading recreational dives, particularly in a professional capacity, and is a qualification used in many parts of the world in recreational scuba diving for a diver who has supervisory responsibility for a group of divers and as a dive guide. As well as being a generic term, 'Divemaster' is the title of the first professional rating of many training agencies, such as PADI, SSI, SDI, NASE, except NAUI, which rates a NAUI Divemaster under a NAUI Instructor but above a NAUI Assistant Instructor. The divemaster certification is generally equivalent to the requirements of ISO 24801-3 Dive Leader.

    The BSAC recognizes several agencies' divemaster certificates as equivalent to BSAC Dive Leader, but not to BSAC Advanced Diver. The converse may not be true.

    The certification is a prerequisite for training as an instructor in recreational diving with the professional agencies except NAUI, where it is an optional step, because of the different position of the NAUI Divemaster in the NAUI hierarchy. (Full article...)
  • US Navy Diver being decontaminated after a dive. If the contamination was severe, the decontamination team would have been wearing hazmat gear.

    Hazmat diving is underwater diving in a known hazardous materials environment. The environment may be contaminated by hazardous materials, the diving medium may be inherently a hazardous material, or the environment in which the diving medium is situated may include hazardous materials with a significant risk of exposure to these materials to members of the diving team. Special precautions, equipment and procedures are associated with hazmat diving so that the risk can be reduced to an acceptable level. These are based on preventing contact of the hazardous materials with the divers and other personnel, generally by encapsulating the affected personnel in personal protective equipment (PPE) appropriate to the hazard, and by effective decontamination after contact between the PPE and the hazardous materials.

    There are a few well known environments, like nuclear power plant cooling systems, sewage treatment plants and sewers which require routine maintenance by divers, and which are well documented, with well-known and consistent hazards, for which standard operating procedures will have been developed, and other environments where the need for diving work is unusual and the hazards less well documented, and must be managed on a case-by-case basis, following an approved code of practice. Hazmat diving is a particular class of diving in high risk environments, normally only done by specially trained professional divers. (Full article...)

Любительское дайвинг

Индекс любительского дайвинга
  • Ниже приведен список текущих европейских рекордов по плаванию в ластах . Рекорды ратифицированы CMAS Confédération Mondiale des Activités Subaquatiques (Всемирной подводной федерацией). ( Полная статья... )
  • Sharks swimming outside shark-proof cage with people inside

    Shark cage diving is underwater diving or snorkeling where the observer remains inside a protective cage designed to prevent sharks from making contact with the divers. Shark cage diving is used for scientific observation, underwater cinematography, and as a tourist activity. Sharks may be attracted to the vicinity of the cage by the use of bait, in a procedure known as chumming, which has attracted some controversy as it is claimed to potentially alter the natural behaviour of sharks in the vicinity of swimmers.

    Similar cages are also used purely as a protective measure for divers working in waters where potentially dangerous shark species are present. In this application the shark-proof cage may be used as a refuge, or as a diving stage during descent and ascent, particularly during staged decompression where the divers may be vulnerable while constrained to a specific depth in mid-water for several minutes. In other applications a mobile cage may be carried by the diver while harvesting organisms such as abalone. (Full article...)
  • 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...)
  • Diver at the wreck of the Hilma Hooker, Netherlands Antilles.


    Wreck diving is recreational diving where the wreckage of ships, aircraft and other artificial structures are explored. The term is used mainly by recreational and technical divers. Professional divers, when diving on a shipwreck, generally refer to the specific task, such as salvage work, accident investigation or archaeological survey. Although most wreck dive sites are at shipwrecks, there is an increasing trend to scuttle retired ships to create artificial reef sites. Diving to crashed aircraft can also be considered wreck diving. The recreation of wreck diving makes no distinction as to how the vessel ended up on the bottom.

    Some wreck diving involves penetration of the wreckage, making a direct ascent to the surface impossible for a part of the dive. (Full article...)

  • Underwater rugby match in Norway.

    Underwater rugby (UWR) is an underwater team sport in which two teams compete to score a negatively buoyant ball (filled with saltwater) into the opponents’ goal at the bottom of a swimming pool. It originated from the physical fitness training programs in German diving clubs during the early 1960s. Recognised by the Confédération Mondiale des Activités Subaquatiques (CMAS) in 1978, It was first played in a world championship in 1980. (Full article...)
  • Recreational diver over a coral reef in the Red Sea

    Recreational dive sites are specific places that recreational scuba divers go to enjoy the underwater environment or for training purposes. They include technical diving sites beyond the range generally accepted for recreational diving. In this context all diving done for recreational purposes is included. Professional diving tends to be done where the job is, and with the exception of diver training and leading groups of recreational divers, does not generally occur at specific sites chosen for their easy access, pleasant conditions or interesting features.

    Recreational dive sites may be found in a wide range of bodies of water, and may be popular for various reasons, including accessibility, biodiversity, spectacular topography, historical or cultural interest and artifacts (such as shipwrecks), and water clarity. Tropical waters of high biodiversity and colourful sea life are popular recreational diving tourism destinations. South-east Asia, the Caribbean islands, the Red Sea and the Great Barrier Reef of Australia are regions where the clear, warm, waters, reasonably predictable conditions and colourful and diverse sea life have made recreational diving an economically important tourist industry.

    Recreational divers may accept a relatively high level of risk to dive at a site perceived to be of special interest. Wreck diving and cave diving have their adherents, and enthusiasts will endure considerable hardship, risk and expense to visit caves and wrecks where few have been before. Some sites are popular almost exclusively for their convenience for training and practice of skills, such as flooded quarries. They are generally found where more interesting and pleasant diving is not locally available, or may only be accessible when weather or water conditions permit.

    While divers may choose to get into the water at any arbitrary place that seems like a good idea at the time, a popular recreational dive site will usually be named, and a geographical position identified and recorded, describing the site with enough accuracy to recognise it, and hopefully, find it again. (Full article...)
  • Underwater orienteering, also known as scuba 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...)

  • US Navy servicemen practise underwater search and rescue scenarios involving combative or panicky victims, which corresponds to certain aquathlonic disciplines

    Aquathlon (also known as underwater wrestling) is an underwater sport, where two competitors wearing masks and fins wrestle underwater in an attempt to remove a ribbon from each other's ankle band in order to win the bout. The "combat" takes place in a 5-metre (16 ft) square ring within a swimming pool, and is made up of three 30-second rounds, with a fourth round played in the event of a tie. The sport originated during the 1980s in the former USSR (now Russia) and was first played at international level in 1993. It was recognised by the Confédération Mondiale des Activités Subaquatiques (CMAS) in 2008. Combat aquathlon practice training engagements not only under water, but also afloat, above the water surface, both with or without diving gear, utilizing dummy weapons (rubber knives, bayonetted rifles, etc.) or barehanded, combined with grappling and choking techniques in order to neutralize or submit the opponent. (Full article...)
  • 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...)
  • 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...)
  • 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, in 1980 at Duke University to provide 24/7 telephone 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 were at the now defunct Rubicon Research Repository.[needs update]
    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...)
  • Underwater ice hockey (also called sub-aqua ice hockey) is a minor extreme sport that is a variant of ice hockey. It is played upside-down underneath frozen pools or ponds. Participants wear diving masks, fins, and wetsuits and use the underside of the frozen surface as the playing area or rink for a floating puck. Competitors do not use any breathing apparatus but instead surface for air every 30 seconds or so.

    It is not to be confused with underwater hockey, in which the floor of a swimming pool and a sinking puck are used. (Full article...)
  • Underwater Target Shooting is an underwater sport/shooting sport that tests a competitors’ ability to accurately use a speargun via a set of individual and team events conducted in a swimming pool using freediving or Apnoea technique. The sport was developed in France during the early 1980s and is currently practiced mainly in Europe. It is known as Tir sur cible subaquatique in French and as Tiro al Blanco Subacuático in Spanish. (Full article...)
  • 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...)

  • 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, World Underwater Federation). 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...)

Опасности, инциденты, безопасность и закон при погружениях

Индекс безопасности дайвинга
  • Вынос ила или иловый выход — это ситуация, когда подводная видимость быстро снижается до функционального нуля из-за взмучивания мелкодисперсных отложений на дне или других твердых поверхностях. Это может произойти при погружении с аквалангом или погружении с поверхности , или при работе с ROV и подводными аппаратами , и представляет собой более серьезную опасность для подводного плавания в ситуациях проникновения , когда путь к поверхности может быть скрыт. ( Полная статья... )
  • 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...)
  • 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...)
  • 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...)
  • 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...)
  • Human factors are the physical or cognitive properties of individuals, or social behavior which is specific to humans, and which 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.
    Human factors include both the non-technical skills that enhance safety and the non-technical factors that contribute to undesirable incidents that put the diver at risk.

    [Safety is] An active, adaptive process which involves making sense of the task in the context of the environment to successfully achieve explicit and implied goals, with the expectation that no harm or damage will occur. – G. Lock, 2022



    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 professional scuba diving is due to these factors. The study also concluded that it would be impossible to eliminate absolutely all minor contraindications for scuba diving, as this would result in overwhelming bureaucracy and would bring all diving to a halt.

    Human factors engineering (HFE), also known as human factors and ergonomics, is the application of psychological and physiological principles to the engineering and design of equipment, procedures, processes, and systems. Primary goals of human factors engineering are to reduce human error, increase productivity and system availability, and enhance safety, health and comfort with a specific focus on the interaction between the human and equipment. (Full article...)
  • 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...)
  • Beaching a casualty while providing artificial respiration


    Diver rescue, usually following an accident, is the process of avoiding or limiting further exposure to diving hazards and bringing a diver to a place of safety. A safe place generally means a place where the diver cannot drown, such as a boat or dry land, where first aid can be administered and from which professional medical treatment can be sought. In the context of surface supplied diving, the place of safety for a diver with a decompression obligation is often the diving bell.

    Rescue may be needed for various reasons where the diver becomes unable to manage an emergency, and there are several stages to a rescue, starting with recognising that a rescue is needed. In some cases the dive buddy identifies the need by personal observation, but in the more general case identification of the need is followed by locating the casualty. The most common and urgent diving emergencies involve loss of breathing gas, and the provision of emergency gas is the usual response. On other occasions the diver may be trapped and must be released by the rescuer. These first responses are usually followed by recovery of the distressed diver, who may be unconscious, to a place of safety with a secure supply of breathing gas, and following rescue, it may be necessary to evacuate the casualty to a place where further treatment is possible.

    Recommended procedures for recovering a disabled or unresponsive scuba diver to the surface have varied over time, and to some extent depend on circumstances and the equipment in use. None are guaranteed to be successful.

    In all rescue operations, the rescuer must take care of their own safety and avoid becoming another casualty. In professional diving the supervisor is responsible for initiating rescue procedures, and for ensuring the safety of the dive team. The rescue is generally carried out by the stand-by diver, and for this reason the stand-by diver must be willing and competent to perform any reasonably foreseeable rescue that may be required for a planned diving operation. A similar level of competence is desirable, but not required of recreational divers, who generally have a poorly defined duty of care to other divers, and are usually only trained in rescue and first aid as optional specialties. Nevertheless, recreational divers are usually advised by their training agencies to dive as buddy pairs so they can assist each other if one gets into difficulty. (Full article...)
  • 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...)
  • 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...)
  • Hazard control methods at the top of the graphic are potentially more effective and protective than those at the bottom. Following this hierarchy of controls 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:
    The system is not based on evidence of effectiveness; rather, it relies on whether the elimination of hazards is possible. Eliminating hazards allows workers to be free from the need to recognize and protect themselves against these dangers. Substitution is given lower priority than elimination because substitutes may also present hazards. Engineering controls depend on a well-functioning system and human behavior, while administrative controls and personal protective equipment are inherently reliant on human actions, making them less reliable. (Full article...)
  • lockout tagout
    Lockout Tagout hasp can accommodate up to 6 padlocks, can be used during group LOTO procedure.

    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 that worker 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...)
  • 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...)
  • A task load indicates the degree of difficulty experienced when performing a task, and task loading describes the accumulation of tasks that are necessary to perform an operation. A light task loading can be managed by the operator with capacity to spare in case of contingencies. Task loads are primarily associated with underwater diving. They are also associated with workloads in other environments, such as aircraft cockpits and command and control stations.

    Task loads may be measured and compared. NASA uses six sub-scales in their task load rating procedure. Three of these relate to the demands on the subject and the other three to interactions between subject and task. Ratings contain a large personal component and may vary considerably between subjects, and over time as experience is gained.
    1. Mental Demands: How much mental and perceptual effort is required;
    2. Physical Demands: How much physical effort is required;
    3. Temporal Demands: How much time pressure the subject feels;
    4. Own Performance: Rating of how successfully the task was performed;
    5. Effort: Rating of how much effort was put into the task; and
    6. Frustration: Rating of how frustrating or satisfying the task was to perform.


    In underwater diving, task loading increases the risk of failure by the diver to undertake some key basic function which would normally be routine for safety underwater. A heavy task loading may overwhelm the diver if something does not go according to plan. This is particularly a problem in scuba diving, where the breathing gas supply is limited and delays may cause decompression obligations. The same workload may be a light task loading to a skilled diver with considerable experience of all the component tasks, and heavy task loading for a diver with little experience of some of the tasks.

    Excessive task loading is implicated in many diving accidents, and may be limited by adding tasks one at a time, and adequately developing the requisite skills for each before adding more. (Full article...)
  • 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...)

Водолазная медицина, расстройства и лечение

Индекс водолазной медицины, расстройств и лечения
  • Мониторинг декомпрессионной камеры во время имитации чрезвычайной ситуации


    Графики гипербарического лечения или таблицы гипербарического лечения представляют собой запланированные последовательности событий в хронологическом порядке для воздействия гипербарического давления, определяющие профиль давления с течением времени и дыхательный газ, который будет использоваться в течение определенных периодов времени для медицинского лечения. Гипербарическая терапия основана на воздействии давления, превышающего нормальное атмосферное давление, и во многих случаях на использовании дыхательных газов с содержанием кислорода, превышающим содержание кислорода в воздухе.

    Большое количество графиков гипербарического лечения предназначено в первую очередь для лечения подводных водолазов и работников гипербарической среды, у которых проявляются симптомы декомпрессионной болезни во время или после погружения или гипербарической смены, но гипербарическая кислородная терапия может также использоваться при других состояниях.

    Большая часть гипербарического лечения проводится в барокамерах , где можно контролировать опасности окружающей среды, но иногда лечение проводится в полевых условиях путем рекомпрессии в воде , когда подходящая камера не может быть достигнута вовремя. Риски рекомпрессии в воде включают поддержание запасов газа для нескольких водолазов и людей, способных ухаживать за больным пациентом в воде в течение длительного периода времени. ( Полная статья... )

  • Laryngospasm is an uncontrolled or involuntary muscular contraction (spasm) of the vocal folds. It may be triggered when the vocal cords or the area of the trachea below the vocal folds detects the entry of water, mucus, blood, or other substance. It may be associated with stridor or retractions. (Full article...)
  • In aviation and underwater diving, alternobaric vertigo is dizziness resulting from unequal pressures being exerted between the ears due to one Eustachian tube being less patent than the other. (Full article...)
  • In physiology, isobaric counterdiffusion (ICD) is the diffusion of different gases into and out of tissues while under a constant ambient pressure, after a change of gas composition, and the physiological effects of this phenomenon. The term inert gas counterdiffusion is sometimes used as a synonym, but can also be applied to situations where the ambient pressure changes. It has relevance in mixed gas diving and anesthesiology. (Full article...)
  • 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...)

  • 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.


    Many people are affected with sufficient motion and some people will experience motion sickness at least once in their lifetime. Susceptibility, however, is variable, with about one-third of the population being susceptible while the other people are affected only under very 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...)

  • Carbon monoxide

    Carbon monoxide poisoning typically occurs from breathing in carbon monoxide (CO) at excessive levels. Symptoms are often described as "flu-like" and commonly include headache, dizziness, weakness, vomiting, chest pain, and confusion. Large exposures can result in loss of consciousness, arrhythmias, seizures, or death. The classically described "cherry red skin" rarely occurs. Long-term complications may include chronic fatigue, trouble with memory, and movement problems.


    CO is a colorless and odorless gas which is initially non-irritating. It is produced during incomplete burning of organic matter. This can occur from motor vehicles, heaters, or cooking equipment that run on carbon-based fuels. Carbon monoxide primarily causes adverse effects by combining with hemoglobin to form carboxyhemoglobin (symbol COHb or HbCO) preventing the blood from carrying oxygen and expelling carbon dioxide as carbaminohemoglobin. Additionally, many other hemoproteins such as myoglobin, Cytochrome P450, and mitochondrial cytochrome oxidase are affected, along with other metallic and non-metallic cellular targets.

    Diagnosis is typically based on a HbCO level of more than 3% among nonsmokers and more than 10% among smokers. The biological threshold for carboxyhemoglobin tolerance is typically accepted to be 15% COHb, meaning toxicity is consistently observed at levels in excess of this concentration. The FDA has previously set a threshold of 14% COHb in certain clinical trials evaluating the therapeutic potential of carbon monoxide. In general, 30% COHb is considered severe carbon monoxide poisoning. The highest reported non-fatal carboxyhemoglobin level was 73% COHb.


    Efforts to prevent poisoning include carbon monoxide detectors, proper venting of gas appliances, keeping chimneys clean, and keeping exhaust systems of vehicles in good repair. Treatment of poisoning generally consists of giving 100% oxygen along with supportive care. This procedure is often carried out until symptoms are absent and the HbCO level is less than 3%/10%.


    Carbon monoxide poisoning is relatively common, resulting in more than 20,000 emergency room visits a year in the United States. It is the most common type of fatal poisoning in many countries. In the United States, non-fire related cases result in more than 400 deaths a year. Poisonings occur more often in the winter, particularly from the use of portable generators during power outages. The toxic effects of CO have been known since ancient history. The discovery that hemoglobin is affected by CO emerged with an investigation by James Watt and Thomas Beddoes into the therapeutic potential of hydrocarbonate in 1793, and later confirmed by Claude Bernard between 1846 and 1857. (Full article...)

  • 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...)
  • 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...)

  • 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 partial 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 ambient pressure divers, although susceptibility varies widely among individuals and from dive to dive. The main modes of underwater diving that deal with its prevention and management 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. To dive at greater depths, as narcosis and oxygen toxicity become critical risk factors, gas mixtures such as trimix or heliox are used. These mixtures prevent or reduce narcosis by replacing some or all of the inert fraction of the breathing gas with non-narcotic helium.
    There is a synergy between carbon dioxide toxicity, and inert gas narcosis which is recognised but not fully understood. Conditions where high work of breathing due to gas density occur tend to exacerbate this effect. (Full article...)
  • Decompression Illness (DCI) comprises two different conditions caused by rapid decompression of the body. These conditions present similar symptoms and require the same initial first aid. Scuba divers are trained to ascend slowly from depth to avoid DCI. Although the incidence is relatively rare, the consequences can be serious and potentially fatal, especially if untreated. (Full article...)
  • PC-based spirometer output

    Fitness to dive (more specifically medical fitness to dive) refers to the medical and physical suitability of a diver to function safely in an underwater environment using diving equipment and related procedures. Depending on the circumstances, it may be established with a signed statement by the diver that they do not have any of the listed disqualifying conditions. The diver must be able to fulfill the ordinary physical requirements of diving as per the detailed medical examination by a physician registered as a medical examiner of divers following a procedural checklist. A legal document of fitness to dive issued by the medical examiner is also necessary.

    The most important medical is the one before starting diving, as the diver can be screened to prevent exposure in the event of an imminent danger. The other important medicals are after some significant illness, where medical intervention is needed and has to be done by a doctor proficient in diving medicine, and can not be done by prescriptive rules.

    Psychological factors can affect fitness to dive, particularly where they affect response to emergencies, or risk-taking behavior. The use of medical and recreational drugs can also influence fitness to dive, both for physiological and behavioral reasons. In some cases, prescription drug use might have a net positive effect when viably treating an underlying condition. However, the side effects of viable medication frequently have undesirable influences on the fitness of a diver. Most cases of recreational drug use result in an impaired fitness to dive, and a significantly increased risk of sub-optimal response to emergencies. (Full article...)
  • Dysbarism refers to medical conditions resulting from changes in ambient pressure. Various activities are associated with pressure changes. Underwater diving is the most frequently cited example, but pressure changes also affect people who work in other pressurized environments (for example, caisson workers), and people who move between different altitudes. (Full article...)
  • 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...)

  • Main symptoms of carbon dioxide toxicity, by increasing volume percent in air.

    Hypercapnia (from the Greek hyper = "above" or "too much" and kapnos = "smoke"), also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood. Carbon dioxide is a gaseous product of the body's metabolism and is normally expelled through the lungs. Carbon dioxide may accumulate in any condition that causes hypoventilation, a reduction of alveolar ventilation (the clearance of air from the small sacs of the lung where gas exchange takes place) as well as resulting from inhalation of CO2. Inability of the lungs to clear carbon dioxide, or inhalation of elevated levels of CO2, leads to respiratory acidosis. Eventually the body compensates for the raised acidity by retaining alkali in the kidneys, a process known as "metabolic compensation".

    Acute hypercapnia is called acute hypercapnic respiratory failure (AHRF) and is a medical emergency as it generally occurs in the context of acute illness. Chronic hypercapnia, where metabolic compensation is usually present, may cause symptoms but is not generally an emergency. Depending on the scenario both forms of hypercapnia may be treated with medication, with mask-based non-invasive ventilation or with mechanical ventilation.

    Hypercapnia is a hazard of underwater diving associated with breath-hold diving, scuba diving, particularly on rebreathers, and deep diving where it is associated with increased breathing gas density due to the high ambient pressure. (Full article...)

Подводные инструменты и оружие

Индекс подводных инструментов и оружия
  • Мина -лимпет — это тип морской мины, прикрепляемой к цели с помощью магнитов . Она так названа из-за своего внешнего сходства с формой лимпета , типа морской улитки , которая крепко цепляется за камни или другие твердые поверхности.

    Пловец или ныряльщик может прикрепить мину, которая обычно имеет полые отсеки, чтобы придать мине лишь небольшую отрицательную плавучесть , что облегчает обращение с ней под водой. ( Полная статья... )

  • 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...)
  • 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 usually 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:
    • 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...)

  • 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 is scarce and can cost over $200 per round. (Full article...)
  • 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...)

  • APS underwater rifle with 5.66-mm cartridge

    The APS underwater assault rifle (APS stands for Avtomat Podvodny Spetsialnyy (Автомат Подводный Специальный) or "Special Underwater Assault Rifle") is an underwater firearm designed by the Soviet Union in the early 1970s. It was adopted in 1975. Made by the Tula Arms Plant (Тульский Оружейный Завод, Tul'skiy Oruzheynyy Zavod) in Russia, it is exported by Rosoboronexport.

    Under water, ordinary bullets are inaccurate and have a very short range. The APS fires a 120-millimetre-long (4.7 in), 5.66 mm calibre steel bolt specially designed for this weapon. Its magazine holds 26 rounds. The APS's barrel is not rifled; the fired projectile is kept in line by hydrodynamic effects; as a result, the APS is somewhat inaccurate when fired out of water.

    The APS has a longer range and more penetrating power than spearguns. This is useful in such situations such as shooting an opposing diver through a reinforced dry suit, a protective helmet (whether air-holding or not), thick tough parts of breathing sets and their harnesses, and the plastic casings and transparent covers of some small underwater vehicles.

    The APS is more powerful than a pistol, but is bulkier, heavier and takes longer to aim, particularly swinging its long barrel and large flat magazine sideways through water. (Full article...)

  • 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...)
  • 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...)

  • The ASM-DT Underwater Assault Rifle

    The ASM-DT is a Russian prototype folding-stock underwater firearm. It emerged in the 1990s. (Full article...)
  • 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...)
  • 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 a type of 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...)

  • OS P11

    The Heckler & Koch P11 is an underwater firearm developed in 1976 by Heckler & Koch. It is loaded using a pepper-box-like assembly, containing five sealed barrels each containing an electrically-fired projectile. Two styles of barrel assembly can be used: one containing five 7.62×36mm flechette darts for use underwater, or five 133-grain bullets for use above water. (Full article...)
  • 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...)

  • 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...)
  • ROV at work in an underwater oil and gas field. The ROV is using a torque wrench to adjust a valve on a subsea structure.

    A remotely operated underwater vehicle (ROUV) or remotely operated vehicle (ROV) is a free-swimming submersible craft used to perform underwater observation, inspection and physical tasks such as valve operations, hydraulic functions and other general tasks within the subsea oil and gas industry, military, scientific and other applications. ROVs can also carry tooling packages for undertaking specific tasks such as pull-in and connection of flexible flowlines and umbilicals, and component replacement. They are often used to visit wrecks at great depths beyond the capacities of submersibles for research purposes, such as the Titanic, amongst others. (Full article...)

История подводного плавания

Указатель истории подводного плавания
  • Аквалангист конца 1960-х годов.

    История подводного плавания тесно связана с историей оборудования . К началу двадцатого века были разработаны две основные архитектуры подводных дыхательных аппаратов: оборудование с открытым циклом, в котором выдыхаемый дайвером газ выбрасывается непосредственно в воду, и дыхательный аппарат с закрытым циклом, в котором углекислый газ дайвера отфильтровывается из выдыхаемого дыхательного газа, который затем рециркулируется, и добавляется больше газа для пополнения содержания кислорода. Оборудование с закрытым циклом было легче адаптировать для подводного плавания в отсутствие надежных, портативных и экономичных сосудов для хранения газа высокого давления. К середине двадцатого века баллоны высокого давления стали доступны, и появились две системы для подводного плавания: акваланг с открытым циклом , в котором выдыхаемый дайвером воздух выбрасывается непосредственно в воду, и акваланг с закрытым циклом , в котором углекислый газ удаляется из выдыхаемого дайвером воздуха, который затем насыщается кислородом и рециркулируется. Кислородные ребризеры имеют серьезные ограничения по глубине из-за риска отравления кислородом, который увеличивается с глубиной, а доступные системы для смешанных газовых ребризеров были довольно громоздкими и разработаны для использования с водолазными шлемами. Первый коммерчески практичный ребризёр для подводного плавания был спроектирован и построен инженером-водолазом Генри Флёссом в 1878 году, когда он работал на Siebe Gorman в Лондоне. Его автономный дыхательный аппарат состоял из резиновой маски, подсоединенной к дыхательному мешку, с предполагаемым 50–60% кислорода, подаваемого из медного бака, и углекислого газа, очищаемого путем пропускания его через пучок веревочной пряжи, пропитанной раствором едкого калия. В 1930-х годах и на протяжении всей Второй мировой войны британцы, итальянцы и немцы разрабатывали и широко использовали кислородные ребризеры для оснащения первых водолазов . В США майор Кристиан Дж. Ламбертсен изобрел свободноплавающий кислородный ребризер . В 1952 году он запатентовал модификацию своего аппарата, на этот раз названную SCUBA, аббревиатура от «автономный подводный дыхательный аппарат», что стало общим английским словом для автономного дыхательного оборудования для дайвинга, а позднее и для деятельности с использованием этого оборудования. После Второй мировой войны военные водолазы продолжали использовать ребризеры, поскольку они не создают пузырьков, которые выдавали бы присутствие водолазов. Высокий процент кислорода, используемый этими ранними системами ребризеров, ограничивал глубину, на которой их можно было использовать, из-за риска судорог, вызванных острым отравлением кислородом .

    Хотя работающая система регулятора потребности была изобретена в 1864 году Огюстом Денайрузом и Бенуа Рукейролем, первая система подводного плавания с открытым циклом, разработанная в 1925 году Ивом Ле Приером во Франции, представляла собой систему свободного потока, регулируемую вручную, с низкой выносливостью, что ограничивало практическую полезность системы. В 1942 году, во время немецкой оккупации Франции, Жак-Ив Кусто и Эмиль Ганьян спроектировали первый успешный и безопасный акваланг с открытым циклом, двухшланговую систему, известную как Aqua-Lung . Их система объединила улучшенный регулятор спроса с воздушными баллонами высокого давления. Это было запатентовано в 1945 году. Чтобы продавать свой регулятор в англоязычных странах, Кусто зарегистрировал торговую марку Aqua-Lung, которая сначала была лицензирована компанией US Divers , а в 1948 году — компанией Siebe Gorman из Англии.

    Ранние комплекты подводного плавания обычно снабжались простой подвеской из плечевых ремней и поясного ремня. Многие подвески не имели спинной пластины, и баллоны опирались непосредственно на спину дайвера. Первые аквалангисты погружались без спасательного жилета. В экстренной ситуации им приходилось сбрасывать грузы. В 1960-х годах появились регулируемые спасательные жилеты с плавучестью (ABLJ), которые можно использовать для компенсации потери плавучести на глубине из-за сжатия неопренового гидрокостюма , а также в качестве спасательного жилета , который будет удерживать потерявшего сознание дайвера лицом вверх на поверхности. Первые версии надувались из небольшого одноразового баллона с углекислым газом, позже — из небольшого непосредственно соединенного воздушного баллона. Подача низкого давления от регулятора первой ступени к блоку клапана накачивания/спуска, оральному клапану накачивания и клапану сброса позволяет контролировать объем ABLJ как спасательного жилета. В 1971 году компания ScubaPro представила жилет-стабилизатор . Этот класс спасательных жилетов с плавучестью известен как устройство контроля плавучести или компенсатор плавучести. Спинка и крыло — это альтернативная конфигурация подвесной системы с компенсационной камерой плавучести, известной как «крыло», установленной позади дайвера, зажатой между спинкой и цилиндром или цилиндрами. Такая компоновка стала популярной среди пещерных дайверов, совершающих длительные или глубокие погружения, которым необходимо было нести несколько дополнительных баллонов, поскольку она освобождает переднюю и боковые стороны дайвера для другого оборудования, которое можно прикрепить в области, где оно легко доступно. Сайдмаунт — это конфигурация оборудования для дайвинга, которая имеет базовые комплекты акваланга , каждый из которых включает один баллон со специальным регулятором и манометром, установленный рядом с дайвером, прикрепленный к подвесной системе под плечами и вдоль бедер, а не на спине дайвера. Она возникла как конфигурация для продвинутого пещерного дайвинга, поскольку он облегчает проникновение в узкие участки пещеры, так как комплекты можно легко снять и переустановить при необходимости. Погружение с боковой подвеской стало популярным в сообществе технических дайверов для общего декомпрессионного погружения и стало популярной специальностью для любительского дайвинга.

    В 1950-х годах ВМС США (USN) задокументировали процедуры военного использования того, что сейчас называется нитроксом, а в 1970 году Морган Уэллс из NOAA начал вводить процедуры погружения с обогащенным кислородом воздухом. В 1979 году NOAA опубликовало процедуры научного использования нитрокса в Руководстве по дайвингу NOAA. В 1985 году IAND (Международная ассоциация дайверов на нитроксе) начала обучать использованию нитрокса для любительского дайвинга. После первоначального сопротивления некоторых агентств использование одной смеси нитрокса стало частью любительского дайвинга, а несколько газовых смесей стали обычным явлением в техническом дайвинге для сокращения общего времени декомпрессии. Токсичность кислорода ограничивает глубину при дыхании смесями нитрокса. В 1924 году ВМС США начали исследовать возможность использования гелия, и после экспериментов на животных люди, дышавшие гелиоксом 20/80 (20% кислорода, 80% гелия), успешно декомпрессировались после глубоких погружений. Дайверы-спелеологи начали использовать тримикс, чтобы обеспечить более глубокие погружения, и он широко использовался в проекте Wakulla Springs 1987 года и распространился на северо-восточное американское сообщество дайверов, занимающихся поиском затонувших объектов. Проблемы более глубоких погружений и более длительных проникновений, а также большие объемы дыхательного газа, необходимые для этих профилей погружений, и доступность кислородных сенсорных ячеек, начиная с конца 1980-х годов, привели к возрождению интереса к дайвингу с ребризером. Благодаря точному измерению парциального давления кислорода стало возможным поддерживать и точно контролировать пригодную для дыхания газовую смесь в контуре на любой глубине. В середине 1990-х годов на рынке любительского подводного плавания появились ребризеры полузамкнутого цикла, за которыми на рубеже тысячелетий последовали ребризеры замкнутого цикла. В настоящее время (2018 г.) ребризеры производятся для военного, технического и любительского подводного плавания. ( Полная статья... )
  • 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...)
  • The painting "An Experiment on a Bird in an Air Pump by Joseph Wright of Derby, 1768, showing a decompression experiment similar to the one performed by Robert Boyle.
    This painting, An Experiment on a Bird in the Air Pump by Joseph Wright of Derby, 1768, depicts an experiment originally performed by Robert Boyle in 1660.


    Decompression in the context of diving derives from the reduction in ambient pressure experienced by the diver during the ascent at the end of a dive or hyperbaric exposure and refers to both the reduction in pressure and the process of allowing dissolved inert gases to be eliminated from the tissues during this reduction in pressure.

    When a diver descends in the water column the ambient pressure rises. Breathing gas is supplied at the same pressure as the surrounding water, and some of this gas dissolves into the diver's blood and other tissues. Inert gas 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, (see: "Saturation diving"), or the diver moves up in the water column and reduces the ambient pressure of the breathing gas until the inert gases dissolved in the tissues are at a higher concentration than the equilibrium state, and start diffusing out again. Dissolved inert gases such as nitrogen or helium can form bubbles in the blood and tissues of the diver if the partial pressures of the dissolved gases in the diver get too high when compared to the ambient pressure. These bubbles, and products of injury caused by the bubbles, can cause damage to tissues generally known as decompression sickness or the bends. 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 also avoid complications due to sub-clinical decompression injury.

    The symptoms of decompression sickness are known to be caused by damage resulting from the formation and growth of bubbles of inert gas within the tissues and by blockage of arterial blood supply to tissues by gas bubbles and other emboli consequential to bubble formation and tissue damage. The precise mechanisms of bubble formation and the damage they 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 usually found to be of some use but not entirely reliable. Decompression remains a procedure with some risk, but this has been reduced and is generally considered to be acceptable for dives within the well-tested range of commercial, military and recreational diving.

    The first recorded experimental work related to decompression was conducted by Robert Boyle, who subjected experimental animals to reduced ambient pressure by use of a primitive vacuum pump. In the earliest experiments the subjects died from asphyxiation, but in later experiments, signs of what was later to become known as decompression sickness were observed. Later, when technological advances allowed the use of pressurisation of mines and caissons to exclude water ingress, miners were observed to present symptoms of what would become known as caisson disease, the bends, and decompression sickness. Once it was recognized that the symptoms were caused by gas bubbles, and that recompression could relieve the symptoms, further work showed that it was possible to avoid symptoms by slow decompression, and subsequently various theoretical models have been derived to predict low-risk decompression profiles and treatment of decompression sickness. (Full article...)
  • 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...)

  • 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...)

  • Rainbow Warrior pictured in Scheveningen in 1979

    The sinking of Rainbow Warrior, codenamed Opération Satanique, was an act of French state-sponsored terrorism. Described as a "covert operation" by the "action" branch of the French foreign intelligence agency, the Directorate-General for External Security (DGSE), the terrorist attack was carried out on 10 July 1985. During the operation, two operatives (both French citizens) sank the flagship of the Greenpeace fleet, Rainbow Warrior, at the Port of Auckland on her way to a protest against a planned French nuclear test in Moruroa. Fernando Pereira, a photographer, drowned on the sinking ship.

    The sinking was a cause of embarrassment to France and President François Mitterrand. They initially denied responsibility, but two French agents were captured by New Zealand Police and charged with arson, conspiracy to commit arson, willful damage, and murder. It resulted in a scandal that led to the resignation of the French Defence Minister Charles Hernu, while the two agents pleaded guilty to manslaughter and were sentenced to ten years in prison. Despite being sentenced to 10 years imprisonment, due to pressures from the French state they spent merely two years confined to the Polynesian island of Hao before being freed by the French government.

    France was also forced to apologise and had to pay reparations to New Zealand, Pereira's family and Greenpeace. (Full article...)

  • USS Westchester County underway, c. 1960

    USS Westchester County (LST-1167) was a Terrebonne Parish-class tank landing ship built for the United States Navy at the tail end of the Korean War. Named for Westchester County, New York, she was the only U.S. Naval vessel to bear the name. The ship served in the Vietnam War and was damaged by limpet mines set by Viet Cong frogmen. It was repaired and later sold to the Turkish Navy and finally sunk as a target in 2014. (Full article...)
  • 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...)
  • 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...)
  • 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...)

  • 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...)

  • 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...)
  • The Russian government committed to raising the wreck and recovering the crew's remains in a US$65-million salvage operation. They contracted with Dutch marine salvage companies Smit International and Mammoet to raise Kursk from the sea floor. It became the largest salvage operation of its type ever accomplished. The salvage operation was extremely dangerous because of the risk of radiation from the reactor. Only seven of the submarine's 24 torpedoes were accounted for. (Full article...)

  • Photos of Argentine forces during the invasion

    The Invasion of the Falkland Islands (Spanish: Invasión de las Islas Malvinas), code-named Operation Rosario (Operación Rosario), was a military operation launched by Argentine forces on 2 April 1982, to capture the Falkland Islands, and served as a catalyst for the subsequent Falklands War. The Argentines mounted amphibious landings and the invasion ended with the surrender of Falkland Government House. (Full article...)

Обучение, регистрация и сертификация водолазов

Индекс обучения, сертификации, регистрации и стандартов водолазов

Подводные водолазные организации

Индекс организаций подводного плавания

Публикации о подводном плавании

Индекс публикаций по подводному плаванию
  • NOAA Diving Manual: Diving for Science and Technology — книга, первоначально опубликованная Министерством торговли США для использования в качестве учебного и оперативного руководства для водолазов Национального управления океанографии и атмосферы. NOAA также публикует Diving Standards and Safety Manual (NDSSM), в котором описываются минимальные стандарты безопасности для их водолазных операций. Было опубликовано несколько изданий руководства по водолазным работам, и несколько редакторов и авторов внесли свой вклад на протяжении многих лет. Книга широко используется в качестве справочного материала профессиональными и любительскими водолазами. ( Полная статья... )
  • 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...)
  • The Last Dive: A Father and Son's Fatal Descent into the Ocean's Depths (2000) is a non-fiction book written by diver Bernie Chowdhury and published by HarperCollins. It documents the fatal dive of Chris Rouse, Sr. and Chris "Chrissy" Rouse, Jr., a father-son team who perished off the New Jersey coast in 1992. The author is a dive expert and was a friend of the Rouses.

    The divers were exploring a German U-boat in 230 feet (70 m) of water off the coast of New Jersey. Although experienced in using technical diving gas mixtures such as "trimix" (adding helium gas to the nitrogen and oxygen found in air), they were diving on just compressed air. The pair had set out to retrieve the captain's log book from the so-called U-Who to "fulfill their dream of diving into fame." The U boat was subsequently identified as U-869.

    Chowdhury is a technical diver who, according to writer Neal Matthews' review of Robert Kurson's book Shadow Divers (2004), "was among the first to adapt cave-diving principles to deep-water wrecks". Also according to Matthews, "His book documents how the clashes of equipment philosophy between cave divers and wreck divers mirrored the clash of diving subcultures." (Full article...)
  • The Darkness Beckons (ISBN 0-939748-32-0) is a book about the history of UK cave diving by Martyn Farr. It is considered the definitive work on the subject. Farr was a major figure in UK diving at a time when many of the original participants were still alive and available for interview. The first edition of the book was published in 1980. A second edition was published in 1991, followed by a substantially rewritten third edition on 3 July 2017. (Full article...)
  • 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...)
  • 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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  • Технические дайверы на декомпрессионной остановке в толще воды
    Водолазы проводят декомпрессию в воде в конце погружения

    Декомпрессия водолаза — это снижение давления окружающей среды , испытываемое во время подъема с глубины. Это также процесс устранения растворенных инертных газов из организма водолаза, которые накапливаются во время подъема, в основном во время пауз в подъеме, известных как декомпрессионные остановки, и после всплытия, пока концентрации газов не достигнут равновесия. Водолазы, дышащие газом при давлении окружающей среды, должны подниматься со скоростью, определяемой их воздействием давления и используемым дыхательным газом. Водолаз, который дышит газом только при атмосферном давлении во время фридайвинга или сноркелинга, обычно не нуждается в декомпрессии. Водолазам, использующим атмосферный водолазный костюм, не нужна декомпрессия, поскольку они никогда не подвергаются высокому давлению окружающей среды. Когда водолаз спускается в воду, гидростатическое давление , а следовательно, и давление окружающей среды, повышаются. Поскольку дыхательный газ подается при давлении окружающей среды , часть этого газа растворяется в крови водолаза и переносится кровью в другие ткани. Инертный газ, такой как азот или гелий, продолжает поглощаться до тех пор, пока растворенный в дайвере газ не придет в состояние равновесия с дыхательным газом в легких дайвера , в этот момент дайвер насыщается для этой глубины и дыхательной смеси, или глубина, а следовательно, и давление, изменяются, или парциальное давление газов изменяется путем изменения дыхательной газовой смеси. Во время подъема окружающее давление снижается, и на каком-то этапе инертные газы, растворенные в любой данной ткани, будут иметь более высокую концентрацию, чем равновесное состояние, и начнут снова диффундировать. Если снижение давления достаточно, избыточный газ может образовывать пузырьки, что может привести к декомпрессионной болезни , возможно изнурительному или опасному для жизни состоянию. Крайне важно, чтобы дайверы управляли своей декомпрессией, чтобы избежать чрезмерного образования пузырьков и декомпрессионной болезни. Неправильно управляемая декомпрессия обычно является результатом слишком быстрого снижения окружающего давления для безопасного удаления количества газа в растворе. Эти пузырьки могут блокировать артериальное кровоснабжение тканей или напрямую вызывать повреждение тканей. Если декомпрессия эффективна, бессимптомные венозные микропузырьки, присутствующие после большинства погружений, удаляются из тела дайвера в альвеолярно-капиллярных руслах.


    легких. Если им не дали достаточно времени или образовалось больше пузырьков, чем можно безопасно удалить, пузырьки увеличиваются в размере и количестве, вызывая симптомы и травмы декомпрессионной болезни. Непосредственная цель контролируемой декомпрессии — избежать развития симптомов образования пузырьков в тканях дайвера, а долгосрочная цель — избежать осложнений из-за субклинической декомпрессионной травмы.


    Механизмы образования пузырьков и повреждения, которые они вызывают, были предметом медицинских исследований в течение значительного времени, и было выдвинуто и проверено несколько гипотез . Были предложены, проверены и использованы таблицы и алгоритмы для прогнозирования результатов графиков декомпрессии для определенных гипербарических воздействий, и во многих случаях заменены. Хотя они постоянно совершенствуются и в целом считаются приемлемо надежными, фактический результат для любого отдельного дайвера остается немного непредсказуемым. Хотя декомпрессия сохраняет некоторый риск, в настоящее время это обычно считается приемлемым для погружений в хорошо проверенном диапазоне обычного любительского и профессионального дайвинга. Тем не менее, популярные в настоящее время процедуры декомпрессии рекомендуют «остановку безопасности» в дополнение к любым остановкам, требуемым алгоритмом, обычно около трех-пяти минут на глубине от 3 до 6 метров (от 10 до 20 футов), особенно 1 при непрерывном подъеме без остановок.


    Декомпрессия может быть непрерывной или поэтапной . Поэтапный подъем декомпрессии прерывается декомпрессионными остановками на расчетных интервалах глубины, но весь подъем фактически является частью декомпрессии, и скорость подъема имеет решающее значение для безвредного устранения инертного газа. Погружение без декомпрессии или, точнее, погружение с безостановочной декомпрессией, основано на ограничении скорости подъема для предотвращения чрезмерного образования пузырьков в самых быстрых тканях. Прошедшее время при поверхностном давлении сразу после погружения также является важной частью декомпрессии и может рассматриваться как последняя декомпрессионная остановка погружения. Организму может потребоваться до 24 часов, чтобы вернуться к нормальным атмосферным уровням насыщения инертным газом после погружения. Время, проведенное на поверхности между погружениями, называется «поверхностным интервалом» и учитывается при расчете требований к декомпрессии для последующего погружения.


    Эффективная декомпрессия требует, чтобы дайвер поднимался достаточно быстро, чтобы установить максимально высокий градиент декомпрессии в максимально возможном количестве тканей, не провоцируя развитие симптоматических пузырьков. Этому способствует максимально допустимое безопасное парциальное давление кислорода в дыхательном газе и избегание изменений газа, которые могут вызвать образование или рост пузырьков контрдиффузии. Разработка графиков, которые являются как безопасными, так и эффективными, осложняется большим количеством переменных и неопределенностей, включая личные различия в реакции на различные условия окружающей среды и рабочую нагрузку. ( Полная статья... )

  • 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...)

  • 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...)

  • 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 re-breather.

    Diving cylinders are usually manufactured from aluminum 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 pressurized, 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 labeling for diving cylinders. Periodic testing and inspection of diving cylinders is often obligatory to ensure the safety of operators of filling stations. Pressurized diving cylinders are considered dangerous goods for commercial transportation, and regional and international standards for colouring and labeling may also apply. (Full article...)
  • 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...)
  • 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...)
  • A diver touches his first finger tip to his thumb tip while extending his other fingers
    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...)

  • 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...)

  • 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...)
  • The painting "An Experiment on a Bird in an Air Pump by Joseph Wright of Derby, 1768, showing a decompression experiment similar to the one performed by Robert Boyle.
    This painting, An Experiment on a Bird in the Air Pump by Joseph Wright of Derby, 1768, depicts an experiment originally performed by Robert Boyle in 1660.


    Decompression in the context of diving derives from the reduction in ambient pressure experienced by the diver during the ascent at the end of a dive or hyperbaric exposure and refers to both the reduction in pressure and the process of allowing dissolved inert gases to be eliminated from the tissues during this reduction in pressure.

    When a diver descends in the water column the ambient pressure rises. Breathing gas is supplied at the same pressure as the surrounding water, and some of this gas dissolves into the diver's blood and other tissues. Inert gas 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, (see: "Saturation diving"), or the diver moves up in the water column and reduces the ambient pressure of the breathing gas until the inert gases dissolved in the tissues are at a higher concentration than the equilibrium state, and start diffusing out again. Dissolved inert gases such as nitrogen or helium can form bubbles in the blood and tissues of the diver if the partial pressures of the dissolved gases in the diver get too high when compared to the ambient pressure. These bubbles, and products of injury caused by the bubbles, can cause damage to tissues generally known as decompression sickness or the bends. 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 also avoid complications due to sub-clinical decompression injury.

    The symptoms of decompression sickness are known to be caused by damage resulting from the formation and growth of bubbles of inert gas within the tissues and by blockage of arterial blood supply to tissues by gas bubbles and other emboli consequential to bubble formation and tissue damage. The precise mechanisms of bubble formation and the damage they 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 usually found to be of some use but not entirely reliable. Decompression remains a procedure with some risk, but this has been reduced and is generally considered to be acceptable for dives within the well-tested range of commercial, military and recreational diving.

    The first recorded experimental work related to decompression was conducted by Robert Boyle, who subjected experimental animals to reduced ambient pressure by use of a primitive vacuum pump. In the earliest experiments the subjects died from asphyxiation, but in later experiments, signs of what was later to become known as decompression sickness were observed. Later, when technological advances allowed the use of pressurisation of mines and caissons to exclude water ingress, miners were observed to present symptoms of what would become known as caisson disease, the bends, and decompression sickness. Once it was recognized that the symptoms were caused by gas bubbles, and that recompression could relieve the symptoms, further work showed that it was possible to avoid symptoms by slow decompression, and subsequently various theoretical models have been derived to predict low-risk decompression profiles and treatment of decompression sickness. (Full article...)
  • Photograph of the cramped interior of a cylinder containing two benches and two diver trainees
    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 34 meters or 112 feet for 32% oxygen). 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...)

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

    Decompression sickness (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. Theoretical 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. (Full article...)

  • 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 partial 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 ambient pressure divers, although susceptibility varies widely among individuals and from dive to dive. The main modes of underwater diving that deal with its prevention and management 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. To dive at greater depths, as narcosis and oxygen toxicity become critical risk factors, gas mixtures such as trimix or heliox are used. These mixtures prevent or reduce narcosis by replacing some or all of the inert fraction of the breathing gas with non-narcotic helium.
    There is a synergy between carbon dioxide toxicity, and inert gas narcosis which is recognised but not fully understood. Conditions where high work of breathing due to gas density occur tend to exacerbate this effect. (Full article...)

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  • Два водолаза в легких шлемах стоят спина к спине на подводной платформе, держась за перила. На фото также видно судно поддержки над поверхностью на заднем плане. (из Outline of underwater diving)
    Водолазы, доставленные с поверхности, едут на платформе к подводному рабочему месту
  • Изображение 2. Подошва ласты, соответствующая немецкому стандарту DIN 7876:1980 (из «Очерка подводного плавания»).
    Подошва ласты, соответствующая немецкому стандарту DIN 7876:1980 (из «Очерка подводного плавания »)
  • Изображение 3Российские и украинские водолазные маски, соответствующие ГОСТ 20568:1975 (из «Очерка по подводному плаванию»)
    Маски для подводного плавания российского и украинского производства, соответствующие ГОСТ 20568:1975 (из «Очерка по подводному плаванию »)
  • Изображение 4. Ассортимент трубок для подводного плавания 1970-х годов, изготовленных по британскому стандарту BS 4532:1969 (из «Очерка подводного плавания»).
    Ассортимент трубок для подводного плавания 1970-х годов, изготовленных по британскому стандарту BS 4532:1969 (из «Очерка подводного плавания» ).

Случайно выбранная цитата

Каждый раз, когда я читаю в отчете об аварии [ sic ], что система напарников дала сбой, я прихожу в ярость. Система напарников не дала сбой, это у людей, которые ее используют, возникают проблемы. Система в порядке, рушится реализация.

—  Глен Эгстром, Аварийное распределение воздуха Эгстром, ГХ (1992). «Аварийное распределение воздуха». Журнал Южно-Тихоокеанского общества подводной медицины . Получено 16 октября 2016 г.

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