Special mark
Appearance
![](http://upload.wikimedia.org/wikipedia/commons/6/60/IALA_specjal_mark.png)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/b2/Buoy_off_Seahill_-_geograph.org.uk_-_720806.jpg/220px-Buoy_off_Seahill_-_geograph.org.uk_-_720806.jpg)
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, (often referred to as a St. Andrews Cross) top-mark. It has a distinctive sequence of various flashes that does not match any other navigational mark flashes in its vicinity.
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
- Cables
- Power 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.
See also
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
Wikimedia Commons has media related to Special marks.
References
- "Special Marks" (PDF). IALA.