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An Isolated Danger Mark, as defined by the 
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.
International Association of Lighthouse Authorities
The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA), previously known as International Association of Lighthouse Authorities, is an intergovernmental organization founded in 1957 to collect and provide naut ...
, is a sea mark
A sea mark, also seamark and navigation mark, is a form of aid to navigation and pilotage that identifies the approximate position of a maritime channel, hazard, or administrative area to allow boats, ships, and seaplanes to navigate safely.
Th ...
used in maritime pilotage
Piloting or pilotage is the process of navigating on water or in the air using fixed points of reference on the sea or on land, usually with reference to a nautical chart or aeronautical chart to obtain a fix of the position of the vessel or air ...
to indicate a hazard to shipping such as a partially submerged rock.
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
*Navigation
Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation, ...
* Lateral mark
A lateral buoy, lateral post or lateral mark, as defined by the International Association of Marine Aids to Navigation and Lighthouse Authorities, is a sea mark used in maritime pilotage to indicate the edge of a channel.
Each mark indicates th ...
* Cardinal mark
Cardinal or The Cardinal may refer to:
Animals
* Cardinal (bird) or Cardinalidae, a family of North and South American birds
**''Cardinalis'', genus of cardinal in the family Cardinalidae
**''Cardinalis cardinalis'', or northern cardinal, th ...
* Safe water mark
Examples of Safe Water Marks
A safe water mark, as defined by the International Association of Lighthouse Authorities, is a sea mark used in maritime pilotage to indicate the end of a channel. They usually imply that open, deep and safe water li ...
* Special mark
A Special Mark, as defined by the International Association of Lighthouse Authorities, is a sea mark used in maritime pilotage. It is recognisable by its yellow colour and X, (also referred to as a St. Andrews Cross or saltire) top-mark. It has a ...
* Emergency wreck buoy
An Emergency wreck buoy is used to warn of a new wreck which has not yet been listed in maritime documents. The buoy is expected to be deployed for the first 24-72 hours after the wreck occurs. After that time more permanent buoyage (such as ...
Footnotes
References
* * {{DEFAULTSORT:Isolated Danger Mark Buoyage