Cardinal marks

Cardinal marks indicate that navigable water lies to the named cardinal side of a danger:

North

East

South

West

Their black/yellow bands, cone topmarks and quick or very-quick light groups encode the quadrant.

They are recognized in international chart symbology and can be relevant in U.S.-connected navigation contexts, but they are not the primary lateral marking system most recreational boaters encounter on ordinary U.S. IALA-B waterways.

Do not omit them from the reference library, but do not teach them as if they replace the ordinary U.S. lateral system.