Question 1

In open water during daylight with good visibility, you sight a vessel ahead displaying a black ball shape forward. What does this shape indicate under the COLREGS, and what action should you consider as a result?

Accepted Answer

A single black ball indicates a vessel at anchor (Rule 30) — you should keep clear of the anchored vessel and be aware that vessels may be working around it (e.g. tenders, divers) requiring extra caution as you pass Rule 30 requires vessels at anchor to display a black ball (forward, where seen) by day. Recognising this shape allows other vessels to anticipate that the vessel is stationary and that activity (tenders, swimmers, divers) may be occurring around it.

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.