MCA CoC COLREGs & Watchkeeping 2

Question 1

What lights must a vessel at anchor display?

Accepted Answer

An all-round white anchor light at the forward part of the vessel and, if 50m or more, a second all-round white light aft and lower

Answer

A vessel at anchor (not underway) shows an all-round white light at the fore part. If 50m or longer, a second all-round white light is shown aft and at a lower position. No sidelights or stern light are shown while at anchor.

Question 2

What sound signal does a vessel sound in restricted visibility when making way through the water?

Accepted Answer

One prolonged blast every two minutes

Answer

A power-driven vessel making way through the water in restricted visibility sounds one prolonged blast at intervals not exceeding two minutes (Rule 35). A vessel stopped but not at anchor sounds two prolonged blasts with a two-second interval, at two-minute intervals.

Question 3

What does a vessel sounding 'five or more short blasts' signal under COLREGs?

Accepted Answer

Doubt or danger — the other vessel's intentions are unclear or a collision is considered imminent

Answer

Five (or more) short blasts is the danger or doubt signal (Rule 34d) — used when one vessel does not understand the other's intentions or considers that insufficient action is being taken to avoid collision. It is a warning signal, not a manoeuvring signal.

Question 4

What shape must a vessel under sail but also using an engine display in daylight?

Accepted Answer

A black cone, apex down, in the fore part of the vessel

Answer

A vessel proceeding under sail when also being propelled by machinery (motor-sailing) must display a black cone, apex downwards, in the fore part of the vessel. This makes it clear the vessel is technically a power-driven vessel and must give way accordingly.

Question 5

What is the purpose of Traffic Separation Schemes (TSS) under COLREGs?

Accepted Answer

To organise opposing streams of traffic into separate lanes with a separation zone, reducing the risk of head-on collisions in busy areas

Answer

Traffic Separation Schemes (TSS) establish one-way traffic lanes separated by a central separation zone in busy shipping channels. Vessels must use the correct lane for their direction, reducing head-on encounters. COLREGs Rule 10 governs conduct in TSS.

MCA CoC Practice Test

MCA CoC Practice Test

MCA CoC COLREGs & Watchkeeping 2