These marks are used to indicate the side of a danger (or any other feature) on which it is safe to pass. They may also show where to find the deepest water in the area, or may draw attention to a bend or junction in a channel, or mark the end of a shoal.
Cardinal marks take their name from the cardinal points of the compass and should be passed on the named side of the mark. For example, pass to the north of a north cardinal mark.
Lights: All cardinal marks carry a white light which may be quick flashing (60 or 50 flashes per minute), or very quick flashing (120 or 100 flashes per minute) in the characteristic shown here. The concept of 3, 6 and 9 and is easily remembered if associated with a clock face.
To be passed on the starboard hand when traveling with the buoyage direction
Shape: conical, pillar or spar
Topmark: (if any) a green cone
Light: (if any) green, any rhythm other than that prescribed for a preferred channel marker.
To be passed on the port hand when travelling with the buoyage direction, generally the direction of the flood tide.
Shape: can, pillar or spar
Topmark: (if any) a red can
Light: (if any) red, any rhythm, other than that prescribed for a preferred channel marker.
Undewater Cable Marker:
These are indicated by a white triangle on the foreshore. When in pairs, they indicate the direction of the cable. Do not anchor near these cables. The skipper of a boat that damages a cable is held responsible, with fines up to $100,000.