Question 1

Using ARPA, you note a target with a CPA (Closest Point of Approach) of 0.3nm and a TCPA (Time to CPA) of 12 minutes, on a steady bearing. How should this information inform your assessment of "risk of collision" under Rule 7?

Accepted Answer

A CPA this close, combined with a steady bearing (suggesting CBDR), strongly indicates risk of collision exists under Rule 7 — the vessel should continue to monitor the developing situation closely and be prepared to take early action under the appropriate rule (e.g. Rules 14/15/17) well before the 12-minute TCPA elapses, rather than waiting until the situation is closer A CPA of 0.3nm is generally considered close enough to represent risk of collision for most vessels — Rule 7 requires this to be recognised and acted upon, with "ample time" (Rule 8) meaning action should be taken well before the situation becomes critical, not at the last minute before TCPA.

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.