Navigation and Seamanship (1+1)

4.3.5.4.1.  Special marks

Special marks not primarily intended to assist navigation but to indicate an area or feature referred to in nautical documents. Special marks are yellow. They may carry a yellow ‘X’ top mark, and light used is yellow. Special marks may also be lettered or numbered to indicate their purpose.

Special mark

Meaning: i ndicates special area - could be spoil or foul ground marks, cable or pipeline marks, including outfall (sewage) pipes or a wreck.

Colour: yellow, at night yellow light.

Top mark: single yellow cross.

Light: yellow, any rhythm may be used other than those used for the white light of cardinal, isolated danger or safe water marks.