Collision Regulations (COLREGs) Flashcards

Under Rule 13 of the COLREGs, when is a vessel considered to be overtaking another?

Answer: When coming up with another vessel from a direction more than 22.5 degrees abaft her beam

Rule 13(b) states that a vessel shall be deemed to be overtaking when coming up with another vessel from a direction more than 22.5 degrees abaft the other vessel's beam — that is, in a position from which at night she would be able to see only the sternlight and neither sidelight. The overtaking vessel must keep out of the way until finally past and clear.

What day shape must a vessel at anchor display under the COLREGs?

Answer: One black ball in the fore part of the vessel

Rule 30(a) requires a vessel at anchor to display in the fore part where it can best be seen, a black ball shape. Vessels of 50 metres or more must also display an anchor light at the stern lower than the forward anchor light. The ball shape is one of the simplest day signals in the COLREGs.

Rule 6 of the COLREGs addresses 'Safe Speed'. Which of the following is NOT listed as a factor to be taken into account when determining safe speed?

Answer: The commercial urgency of the voyage

Rule 6 lists factors including visibility, traffic density, manoeuvrability of the vessel, background light at night, wind/sea/current conditions, draught relative to depth, and radar characteristics. Commercial urgency is explicitly NOT a factor — safe speed is determined solely by navigational safety considerations.

A vessel displays two all-round red lights in a vertical line and also sidelights and a sternlight. Under the COLREGs, what does this indicate?

Answer: A vessel not under command but making way through the water

Under Rule 27(a), a vessel not under command displays two all-round red lights in a vertical line where they can best be seen. When making way through the water, she additionally shows sidelights and a sternlight. When stopped and not making way, only the two red lights are displayed without sidelights or sternlight.

According to Rule 14, what constitutes a head-on situation between two power-driven vessels?

Answer: When each vessel can see both sidelights of the other vessel, or when by night the masthead lights are in line or nearly in line

Rule 14(a) states that when two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision, each shall alter course to starboard so that each passes on the port side of the other. A head-on situation exists when a vessel sees the other ahead or nearly ahead, and by night could see the masthead lights in a line or nearly in line and/or both sidelights.

Under Rule 18, which of the following correctly describes the hierarchy of vessels from most privileged (stand-on) to least privileged (give-way)?

Answer: Not under command, restricted in ability to manoeuvre, constrained by draught, fishing, sailing, power-driven

Rule 18 establishes the hierarchy: A vessel not under command has the highest priority, followed by a vessel restricted in her ability to manoeuvre, then a vessel constrained by her draught, then a vessel engaged in fishing, then a sailing vessel, and finally a power-driven vessel which must give way to all the above categories.