Left to right: North cardinal, East cardinal, South cardinal, West cardinal
Cardinal marks indicate that the deepest water in the area lies to the named side of the mark. They are used in conjunction with the compass to indicate the direction from the mark in which the deepest navigable water lies, to draw attention to a bend, junction or fork in a channel, or to mark the end of a shoal.
There are four types of cardinal mark which indicate the mariner will be safe if they pass;
- North of a North Mark
- South of a South Mark
- East of an East Mark
- West of a West Mark.
Cardinal Marks are also used for permanent wreck marking whereby North, East, South and West Cardinal buoys are placed around the wreck.
In the case of a new wreck, any one of the Cardinal buoys may be duplicated and fixed with a Radar Beacon (RACON).
A South mark cardinal buoy indicating safe passage to the south of the buoy
A cardinal mark buoy being prepared for deployment aboard THV Galatea
Class A cardinal buoy being deployed from THV Galatea
Buoys are available for hire, contact us for more information.