What lights does a vessel not under command show?
Two all-round red lights in a vertical line. By day: two black balls (Rule 27(a)).
Not under command (NUC) means something exceptional, such as a steering or engine failure, stops her manoeuvring as the Rules require. Power, sailing and fishing vessels all keep out of her way (Rule 18).
- Making way through the water: she adds sidelights and a sternlight, but no masthead light.
- Two reds plus anchor lights means aground, not NUC.
- These aren't distress signals.
- In fog: one prolonged and two short blasts at least every 2 minutes.
- Vessels under 12 m needn't show them.
Source: COLREGS Rule 3(f), Rule 18, Rule 27(a) and Rule 35(c).
Test yourself
Rule 21Question 1 of 5
What is the arc of visibility of a masthead (steaming) light?
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