NUC (Not Under Command)
Abbreviation: NUC
COLREG Rule 3(f) status where a vessel is unable to manoeuvre due to exceptional circumstances (steering failure, engine failure) and cannot keep out of the way of another vessel.
Quick facts
- Rule
- COLREG Rule 3(f)
- Lights
- Two red all-round
In practice
OOW displays NUC lights immediately on steering / engine failure + broadcasts urgency signal. Rule of thumb: if you can't keep out of the way, you're NUC.
Regulatory detail & full definition
COLREG Rule 3(f) defines a vessel Not Under Command (NUC) as one which through some exceptional circumstance is unable to manoeuvre as required by the Rules + is therefore unable to keep out of the way of another vessel. NUC vessels display two red all-round lights (or two black balls in daytime) per Rule 27(a). Under Rule 18(a) power-driven vessels must keep out of the way of NUC vessels. NUC is distinct from Restricted in Ability to Manoeuvre (RAM) — RAM covers vessels restricted BY THE NATURE OF THEIR WORK.
Authoritative source: IMO — COLREGs ↗
Related
Source: COLREG
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