Question 1

What does COLREGS Rule 6 (safe speed) require in restricted visibility, independent of a vessel's radar and ARPA fit?

Accepted Answer

A speed that allows proper and effective action to avoid collision and that the vessel can be stopped within a distance appropriate to the circumstances BEA-mer's investigation identified excessive speed — Tricolor was making 17.9 knots while overtaking in fog — as a contributing cause. Rule 6 requires speed to be judged against stopping distance and the prevailing circumstances, not against what the equipment can theoretically track.

Question 2

Rule 5 (Look-out) requires every vessel at all times to maintain a proper look-out by sight and hearing, as well as by all available means appropriate in the prevailing circumstances and conditions — and this duty applies even when the vessel is at anchor in a busy anchorage.

Accepted Answer

True True. Rule 5 applies 'at all times' and to 'every vessel'. A vessel at anchor in a busy anchorage still needs an effective look-out to detect drifting vessels, dragging anchors, or approaching traffic that may pose a risk of collision or contact.

Question 3

Under Rule 6 (Safe Speed), a vessel fitted with a fully operational radar and ARPA never needs to reduce speed in restricted visibility, because the equipment guarantees early detection of other vessels.

Accepted Answer

False False. Rule 6 explicitly lists radar capability as one factor to consider, but also requires accounting for the state of visibility, traffic density, manoeuvrability, and the limitations of radar (range scale, sea/rain clutter, blind sectors). Even a vessel with excellent radar must proceed at a speed that allows proper and effective action to avoid collision and to be stopped within a distance appropriate to the prevailing circumstances.