Rule 30 prescribes lights and shapes for anchored vessels and vessels aground.
- 1in the fore part, an all-round white light or one ball;
- 2at or near the stern and at a lower level than the forward light, another all-round white light.
- 1two all-round red lights in a vertical line;
- 2three balls in a vertical line.
- 1and
- 2.
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
Anchored vessels show a forward all-round white light + a lower one aft (≥50m); <50m may show a single all-round white
The anchor day shape is one black ball, exhibited forward
Aground = anchor signals PLUS two red lights vertically (night) and three balls vertically (day)
≥100m at anchor must illuminate decks; smaller vessels may do so
<7m vessel at anchor outside narrow channels / fairways / anchorages: no anchor lights or ball required
<12m vessel aground: no need to show the two-red and three-balls aground signals (but anchor lights still required if applicable)
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
Forgetting that a <12m vessel aground is exempt from the aground signals but still has anchor obligations
Test Your Knowledge
Test your knowledge and prove your mastery.
More rules in this Part
- Sailing Vessels Underway and Vessels Under OarsSailing vessels show sidelights and sternlight. May optionally show red over green all-round lights at the masthead.
- Fishing VesselsFishing vessels show green over white when trawling, red over white for other fishing, and sidelights plus sternlight when making way.
- Vessels Not Under Command or Restricted in Ability to ManoeuvreNUC shows two red all-round lights vertically. RAM shows red-white-red all-round lights vertically.
- Vessels Constrained by Their DraughtA vessel constrained by draught may display three all-round red lights in a vertical line, or a cylinder day shape.
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