Sea mark indicating a danger spot
Examples of Isolated Danger Marks An Isolated Danger Mark , as defined by the International Association of Lighthouse Authorities , is a sea mark used in maritime pilotage to indicate a hazard to shipping such as a partially submerged rock.
Isolated Danger Mark near Hvar, Croatia It is recognisable by its black and red bands and top-mark of two black balls.
Its distinctive sequence of flashing white light consists of 2 quick flashes in intervals of either 5 or 10 seconds.
See also
Footnotes
References International association of maritime aids to navigation and lighthouse authorities (2010). "Maritime buoyage system and other aids to navigation" (PDF) . IALA-AISM. Retrieved 11 August 2019 . Service Hydrographique et Océanographique de la Marine (1 September 2016). Signalisation Maritime (PDF) (in French). France: SHOM. ISBN 978-2-11-139457-5 . Retrieved 11 August 2019 . Wikimedia Commons has media related to Isolated danger marks .