Special mark
[Image:IALA specjal mark.png|thumb|Examples of Special Marks]
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" top-mark. If a light is fitted the light is always yellow in colour and can have any light characteristic which differs from those used for cardinal marks, isolated danger marks, mobile aid to navigation marks and safe water marks.
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
- Historic wrecks
- Protected areas
- Outfall pipes
- 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.