Question 1

Two power-driven vessels detect each other only by radar in fog, on courses that would constitute a "crossing situation" if visibility were good. Which rule governs their actions — Rule 15 (crossing) or Rule 19 (restricted visibility)?

Accepted Answer

Rule 19 applies — in restricted visibility, Rules 11-18 (the rules for vessels in sight of one another, including Rule 15) do not apply; Rule 19 instead governs, with its own guidance (e.g. Rule 19(d) on alterations to avoid relative to vessels forward of the beam or abeam/aft) tailored to the absence of visual contact Section II of the Rules (Rules 11-18, "Conduct of Vessels in Sight of One Another") explicitly applies only when vessels are in sight of one another — in restricted visibility without visual contact, Rule 19 (Section III) applies instead, with a different framework for assessing and responding to risk.

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.