Special marks

The Special Mark indicates a special area or feature, for example:
Traffic separations, spoil grounds, cable or pipelines, to define a channel for deep draft vessels within a channel, or military exercise zones.
The Special Mark may have a shape of any kind, and is yellow .
As a top mark it has a single yellow “X” shape.
The Special Mark, exhibits a yellow light, and has any rhythm other than those used for the white lights of cardinal, isolated danger and safe water marks, and that cannot be confused with any other light in the area.