IALACOLREG
30

Anchored Vessels and Vessels Aground

Vessel at anchor < 50 m — one all-round white forward; ball by day.
Vessel at anchor < 50 m — one all-round white forward; ball by day.

Rule 30 prescribes lights and shapes for anchored vessels and vessels aground.

a
A vessel at anchor shall exhibit: in the fore part, an all-round white light or one ball; and at or near the stern and at a lower level, another all-round white light. A vessel of less than 50 metres may show a single all-round white light where it can best be seen.
b
A vessel of 100 metres or more at anchor shall also use the available working or equivalent lights to illuminate her decks.
c
A vessel of less than 7 metres at anchor is generally exempt from the anchor light and shape requirement, except when anchored in or near a narrow channel, fairway, anchorage or other area where other vessels normally navigate.
d
A vessel aground shall exhibit the anchor lights and shape plus two all-round red lights and three balls in a vertical line.

An interactive 3D illustration is shown here. The same content is described in the rule text and key takeaways below.

Recognition Sequence

Classify the vessel state first: underway, making way, stopped, at anchor, aground, towing, fishing, pilotage or special condition.

Read special lights vertically from top to bottom before using sidelights and sternlight to confirm aspect.

Then confirm the answer with the day shape, vessel length and any extra signal such as towing lights, deck illumination or a cylinder.

Exam Focus

Avoid identifying a vessel from one colour alone.

Many mistakes come from spotting a red light and guessing before checking the full pattern.

If the question mentions 'making way', 'underway but stopped', 'at anchor' or 'aground', that wording usually determines which extra lights or shapes appear.

Key Takeaways

1

Anchored vessels normally show a forward all-round white light, and for larger vessels a second lower white light aft

2

The anchor day shape is one black ball

3

Aground means anchor signals plus two red lights and three balls

4

Small anchored craft have only a limited exception, not a blanket exemption everywhere

Common Mistakes

Showing only the aground red lights and forgetting the anchor signals

Forgetting the anchor ball by day

Assuming small craft never need anchor lights in navigated waters

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