Rule 30. Anchored and aground

An all-round white light in the fore part and a second all-round white at or near the stern, lower than the first. A ball forward by day.

Set

Two all-round whites: forward higher, aft lower. No sidelights and no sternlight.

Tell

Two whites, no colours, no movement: she is stopped. The height difference shows where her bow is.

Decks

A vessel of 100 m or more must also light her decks with available working lights.

In fog

Rapid ringing of the bell for about 5 seconds at intervals of not more than a minute. From 100 m: bell forward, gong aft.

She may show one all-round white light where it can best be seen.

Set

One all-round white. Ball by day.

Exception

A vessel under 7 m at anchor, when not in or near a narrow channel, fairway, anchorage or where other vessels normally navigate, need not show it.

Risk

A lone white light is easily taken for a small vessel underway: approach carefully.

The anchor lights plus two all-round red lights in a vertical line. Three balls in a vertical line by day.

Set

All-round white anchor lights and two all-round reds.

Tell

Reds together with anchor whites: she is not merely stopped, she is aground. There is shallow water right there.

In fog

The bell as at anchor, plus three separate distinct strokes before and after each rapid ringing.

Exception

A vessel of less than 12 m aground need not show these lights and shapes.