IRPCS Flashcards

Under the International Regulations for Preventing Collisions at Sea, what does Rule 2 'Responsibility' establish?

Answer: Nothing in the rules exonerates any vessel from the consequences of neglecting proper seamanship, good judgement, or the special circumstances of the case

Rule 2 makes clear that the rules do not relieve any vessel of its duty to act responsibly. Even if you are technically the stand-on vessel, you must still exercise good seamanship and common sense.

A vessel displays a red light over a white light over a red light in a vertical line. What does this indicate?

Answer: A vessel restricted in her ability to manoeuvre

Red-White-Red in a vertical line indicates a vessel restricted in her ability to manoeuvre (RAM), such as a vessel engaged in dredging, underwater operations, or towing that restricts her manoeuvrability.

What lights must a sailing vessel display at night when under sail alone?

Answer: Sidelights (green starboard, red port) and a stern light — optionally, red over green at the masthead

A sailing vessel under sail alone must display sidelights and a stern light. Optionally, she may also display an all-round red over all-round green light at the masthead (but not combined with a tricolour).

Under Rule 13, what constitutes an 'overtaking' situation?

Answer: When one vessel approaches another from a direction more than 22.5 degrees abaft the beam — the overtaking vessel must keep clear

An overtaking vessel approaches from more than 22.5° abaft (behind) the beam of the other vessel — essentially from behind. The overtaking vessel must keep clear regardless of whether either is under sail or power.

What does a vessel displaying two black balls in a vertical line indicate during daylight?

Answer: A vessel at anchor

Two black balls displayed in a vertical line is the day shape for a vessel at anchor. Additional ball(s) indicate specific conditions like aground (three balls).

Under Rule 19, what must a vessel do in restricted visibility when it detects another vessel by radar alone?

Answer: Determine if a close-quarters situation is developing and take avoiding action in ample time — if altering course, avoid turning to port for a vessel forward of the beam

In restricted visibility (Rule 19), if radar detects a developing close-quarters situation, the vessel must take early avoiding action. A turn to port should be avoided for a vessel forward of the beam (unless overtaking).