COLREG quiz,
Rules of the Road.
Test yourself on the International Regulations for Preventing Collisions at Sea. Every answer shows the rule it comes from, so you can revise as you go.
24 questions on the Rules of the Road
Pick an answer to see whether it is right and which rule it comes from. Covers sound signals, steering and sailing rules, lights and shapes, traffic separation schemes and restricted visibility.
1. How long is a short blast under the COLREGs?
Rule 32(b): a short blast is a blast of about one second's duration.
2. How long is a prolonged blast?
Rule 32(c): a prolonged blast is a blast of from four to six seconds' duration.
3. Vessels in sight of one another: what does one short blast mean?
Rule 34(a): one short blast means 'I am altering my course to starboard'.
4. What do two short blasts mean?
Rule 34(a): two short blasts mean 'I am altering my course to port'.
5. What do three short blasts mean?
Rule 34(a): three short blasts mean 'I am operating astern propulsion'.
6. What signal do you give if you doubt whether the other vessel is taking sufficient action to avoid collision?
Rule 34(d): at least five short and rapid blasts on the whistle, which may be supplemented by a light signal of at least five short and rapid flashes.
7. In restricted visibility, what does a power-driven vessel making way through the water sound?
Rule 35(a): one prolonged blast at intervals of not more than two minutes.
8. In restricted visibility, a power-driven vessel underway but stopped and not making way sounds:
Rule 35(b): two prolonged blasts in succession with an interval of about 2 seconds between them, at intervals of not more than two minutes.
9. When is a vessel deemed to be overtaking?
Rule 13(b): coming up with another vessel from a direction more than 22.5 degrees abaft her beam, so that at night only the sternlight would be visible.
10. Two power-driven vessels meet on reciprocal or nearly reciprocal courses with risk of collision. What should each do?
Rule 14(a): each shall alter her course to starboard so that each passes on the port side of the other.
11. Two power-driven vessels are crossing with risk of collision. Which one keeps out of the way?
Rule 15: the vessel which has the other on her own starboard side shall keep out of the way and, if circumstances admit, avoid crossing ahead of the other vessel.
12. Over what horizontal arc does a masthead light show?
Rule 21(a): an unbroken light over an arc of the horizon of 225 degrees, from right ahead to 22.5 degrees abaft the beam on either side.
13. Over what arc does a sternlight show?
Rule 21(c): 135 degrees, 67.5 degrees from right aft on each side.
14. Over what arc does each sidelight show?
Rule 21(b): each sidelight shows from right ahead to 22.5 degrees abaft the beam on its side, an arc of 112.5 degrees.
15. What is the minimum range of a masthead light on a vessel of 50 metres or more in length?
Rule 22(a): masthead light 6 miles for vessels of 50 metres or more in length.
16. By day, what shape does a vessel at anchor show?
Rule 30(a): one ball in the fore part of the vessel, where it can best be seen.
17. By day, what does a vessel not under command show?
Rule 27(a)(ii): two balls or similar shapes in a vertical line where they can best be seen.
18. By day, what does a vessel restricted in her ability to manoeuvre show?
Rule 27(b)(ii): three shapes in a vertical line: the highest and lowest are balls and the middle one a diamond.
19. A vessel constrained by her draught may show, in addition to the lights of a power-driven vessel:
Rule 28: three all-round red lights in a vertical line, or by day a cylinder.
20. By day, what does a vessel aground show?
Rule 30(d): three balls in a vertical line. At night, the anchor lights plus two all-round red lights in a vertical line.
21. What are the identifying lights of a pilot vessel on pilotage duty?
Rule 29(a): two all-round lights in a vertical line, the upper white and the lower red. Remember: 'white hat, red nose'.
22. A vessel engaged in trawling shows which all-round lights in a vertical line?
Rule 26(b): two all-round lights in a vertical line, the upper green and the lower white.
23. When crossing a traffic lane in a traffic separation scheme, a vessel shall cross:
Rule 10(c): a vessel shall, so far as practicable, avoid crossing traffic lanes but, if obliged to do so, shall cross on a heading as nearly as practicable at right angles to the general direction of traffic flow.
24. In restricted visibility, a vessel detected by radar alone is forward of your beam and not overtaking. What should you avoid, so far as possible?
Rule 19(d)(i): avoid an alteration of course to port for a vessel forward of the beam, other than for a vessel being overtaken. Rule 19(d)(ii) adds: avoid an alteration towards a vessel abeam or abaft the beam.
Based on the International Regulations for Preventing Collisions at Sea, 1972 (COLREGs), as amended. This quiz is a study aid; always refer to the official text and your national edition for examinations and watchkeeping.
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