Question 1

Under Rule 21, how is a vessel's "masthead light" defined, and what is its significance for identifying vessel type at night?

Accepted Answer

A white light placed over the fore-and-aft centreline showing an unbroken light over a defined arc of the horizon (from 22.5° aft of the beam on each side, i.e. 225°) — its presence (or absence) helps distinguish power-driven vessels underway (which show it) from sailing vessels (which do not) The masthead light's defined arc (225°, forward-facing) and its presence on power-driven vessels but absence on sailing vessels underway is a key visual cue for distinguishing vessel types and orientation at night, central to interpreting many of the lighting rules.

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.