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 distinctive sequence of various flashes that does not match any other navigational mark flashes in its vicinity.
Examples of Special Marks
A Special mark indicating an outfall pipe in the Irish Sea
off Helen's Bay, Northern Ireland.
It has the flashing sequence Fl.(2).Y meaning it flashes yellow twice, this is called group flashing.
Purpose
Special marks can indicate:
- Administrative areas
- Water skiing areas
- Anchorage areas
- Mooring areas
- Waiting areas
- Marine farms
- Oil wells
- Dead ends
- Pipelines
- Spoil ground (an area where dredged material is deposited)
- Historic wrecks
- Protected areas
- Outfall pipes (such as Stormwater, and Cooling water)
- Sewerage pipes
- Intake pipes
- Submarine cables
Other uses
- Buoys, such as a Weather buoy or Mooring buoy are coloured yellow or have a yellow light to indicate it is not an aid to navigation.
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gollark: What feature?
gollark: It used to, very briefly, delete builtins from the bot's python environment, which caused horrible problems and was soon removed.
gollark: The most used feature of my bot is the `++delete` command, which "deletes things", which actually means it just adds them to a searchable list of "deleted items".
See also
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Wikimedia Commons has media related to Special marks. |
References
- "Special Marks" (PDF). IALA. Archived from the original (PDF) on 2007-12-14.
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