AB Rules of the Road & Maritime Regulations 4

Question 1

What is the arc of visibility for a vessel's sidelights?

Accepted Answer

112.5 degrees each side

Answer

Rule 21 defines sidelights as showing from dead ahead to 22.5 degrees abaft the beam — an arc of 112.5 degrees on each side.

Question 2

A vessel towing where the length of tow exceeds 200 meters displays which special day shape?

Accepted Answer

A black diamond

Answer

Rule 24 requires a vessel towing where the length of tow exceeds 200 meters to display a black diamond shape where it can best be seen.

Question 3

Which rule of the COLREGS establishes the duty to maintain a proper lookout?

Accepted Answer

Rule 5

Answer

Rule 5 requires every vessel to maintain a proper lookout by sight and hearing, as well as by all available means, at all times.

Question 4

A vessel using a traffic separation scheme must generally proceed in which direction?

Accepted Answer

In the general direction of traffic flow for that lane

Answer

Rule 10(b) requires vessels using a traffic lane to proceed in the general direction of traffic flow for that lane.

Question 5

Under COLREGS, what is the difference between a 'short blast' and a 'prolonged blast'?

Accepted Answer

Short = 1 sec; Prolonged = 4–6 sec

Answer

Rule 32 defines a short blast as about one second duration and a prolonged blast as from four to six seconds duration.

(AB) Able Seaman Exam Practice Test