Cardinals: name, cones, bands and rhythm

A cardinal mark uses compass directions to indicate where safer water lies relative to the mark and the danger or feature being marked. North, east, south and west refer to geographical orientation, rather than the boat’s heading.

The family keeps the same identity in Regions A and B. It is useful around shoals, dangers, bends or junctions where a north/south reference describes the situation better than channel sides.

All combine black and yellow horizontal bands. The distinctive topmark has two black cones, one above the other.

Their orientation distinguishes the four identities, with the bands confirming that reading. The body is normally pillar or spar, without a unique family shape.

Lights, when fitted, are white and use quick or very quick flashing, organised differently for each cardinal.

Cone points indicate the black areas: north has both points upwards and black at the top; south points downwards with black below. East has outward points and black at the ends.

West has points together and black in the middle. This is a visual memory aid, rather than a replacement for the table.

An awkward photograph angle or damaged cone can make the reading difficult.

For lights, imagine a clock: east is three o’clock, south six, west nine. South adds a long flash after six quick flashes, helping distinguish it from three or nine when observation is incomplete.

North has continuous quick flashing, without these groups. Q and VQ are different classes: R1001 describes Q at 50 or 60 flashes per minute and VQ at 100 or 120.

A long flash lasts at least two seconds; complete periods are those shown in the table.

Quadrants are defined by true bearings from the marked point: NW–NE, NE–SE, SE–SW and SW–NW. A north cardinal indicates its northern side for passing relative to the marked feature.

This does not declare east and west invariably unusable, or measure the danger’s extent or a passing distance. R1001 directs attention to the chart for context.

The diagram identifies the family; it contains neither depths nor a real position.

A second example separates counting from sequence: six quick flashes followed by a long flash identify south, rather than a light with “seven equal flashes”. The long flash is a different kind of phase within the same cycle.

Notation therefore writes Q(6)+LFl to preserve the structure. The table also shows why east and west cannot be distinguished by light colour: both are white but their groups differ.