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Sound signals practice test
25 questions on COLREG Part D: sound-signal equipment, manoeuvring and warning signals, signals in restricted visibility and distress signals. Every answer is explained and linked to its rule.
Reviewed by Ramon Curto, Nautical teacher at IECNPC
- 25 questions
- 20 minutes
- Pass: 20 of 25
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These are IALACOLREG's own study questions, not official exam questions.
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Questions and answers
1.A vessel at anchor in restricted visibility rings the bell rapidly for about 5 seconds. At what intervals?
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Correct answer: A. Not more than one minute
Rule 35(g): a vessel at anchor shall at intervals of not more than one minute ring the bell rapidly for about 5 seconds. Most underway fog signals use intervals of not more than 2 minutes instead.
2.Which spoken radiotelephony distress signal is internationally recognized?
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Correct answer: C. MAYDAY
Rule 37 / Annex IV recognizes the spoken word "MAYDAY" as the radiotelephony distress signal.
3.A vessel has whistles fitted more than 100 metres apart. How must she give manoeuvring and warning signals?
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Correct answer: A. On one of the whistles only
Rule 34(f): if whistles are fitted on a vessel at a distance apart of more than 100 metres, one whistle only shall be used for giving manoeuvring and warning signals.
4.A power-driven vessel underway but stopped and making no way through the water in fog sounds:
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Correct answer: B. Two prolonged blasts in succession at intervals of not more than 2 minutes
Rule 35(b): two prolonged blasts in succession at intervals of not more than 2 minutes.
5.Signals to attract attention must:
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Correct answer: B. Not be mistaken for any prescribed signal or aid to navigation
Rule 36: signals to attract attention must not be mistaken for any other prescribed signal or navigation aid.
6.In restricted visibility, a pilot vessel on pilotage duty may add to her Rule 35(a), (b) or (g) signals an identity signal of:
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Correct answer: C. Four short blasts
Rule 35(k): a pilot vessel when engaged on pilotage duty may, in addition to the signals prescribed in paragraphs (a), (b) or (g), sound an identity signal consisting of four short blasts.
7.Under Rule 36, a vessel trying to attract attention may direct her searchlight beam:
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Correct answer: A. In the direction of the danger, without embarrassing any vessel
Rule 36: any vessel may direct the beam of her searchlight in the direction of the danger, in such a way as not to embarrass any vessel.
8.In the COLREG, what does the word 'whistle' mean (Rule 32)?
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Correct answer: A. Any sound-signalling appliance that can give the prescribed blasts and meets Annex III
Rule 32(a): 'whistle' means any sound-signalling appliance capable of producing the prescribed blasts and complying with the specifications in Annex III, so sound level and audibility are part of the definition.
9.Which sound signal is listed in Annex IV (Rule 37) as a distress signal?
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Correct answer: B. A continuous sounding with any fog-signalling apparatus
Rule 37 / Annex IV: a continuous sounding with any fog-signalling apparatus is a distress signal. Five short and rapid blasts is the Rule 34(d) doubt signal; short-prolonged-short is the Rule 35(g) anchor warning; four short blasts is the Rule 35(k) pilot identity signal.
10.Under Rule 36, which kind of light shall be avoided when attracting another vessel's attention?
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Correct answer: D. High-intensity intermittent or revolving lights, such as strobes
Rule 36: attention signals must not be mistaken for any signal authorized elsewhere in the Rules or for an aid to navigation, and a searchlight may be directed toward the danger. For this purpose the use of high-intensity intermittent or revolving lights, such as strobe lights, shall be avoided.
11.When Rule 34(a) whistle signals are supplemented by light signals, what is the interval between successive signals?
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Correct answer: B. Not less than ten seconds
Rule 34(b)(ii): each flash lasts about one second, the interval between flashes is about one second, and the interval between successive signals is not less than ten seconds.
12.A 'short blast' is defined as a blast of about:
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Correct answer: B. One second
Rule 32(b): a short blast means a blast of about one second's duration.
13.A vessel of less than 12 metres does not carry the appliances of Rule 33(a). What does Rule 33(b) require?
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Correct answer: D. Some other means of making an efficient sound signal
Rule 33(b): a vessel of less than 12 m is not obliged to carry the Rule 33(a) appliances, but if she does not, she shall be provided with some other means of making an efficient sound signal.
14.For a power-driven vessel underway manoeuvring in sight of another vessel, one short whistle blast means:
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Correct answer: B. I am altering course to starboard
Rule 34(a): one short blast means 'I am altering my course to starboard.'
15.Five or more short and rapid blasts mean:
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Correct answer: C. Doubt or danger — the intentions of the other vessel are not understood
Rule 34(d): at least five short and rapid blasts indicate doubt about whether sufficient action is being taken.
16.Rule 33(a) lets the bell or gong be replaced by other equipment with the same sound characteristics, provided that:
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Correct answer: A. Manual sounding of the prescribed signals is always possible
Rule 33(a): the bell or gong or both may be replaced by other equipment having the same respective sound characteristics, provided that manual sounding of the prescribed signals shall always be possible.
17.Annex IV (Rule 37) lists a gun or other explosive signal as a distress signal when it is fired:
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Correct answer: C. At intervals of about one minute
Rule 37 / Annex IV: a gun or other explosive signal fired at intervals of about a minute indicates distress and need of assistance.
18.Under Rule 35(a), a power-driven vessel making way through the water in restricted visibility sounds:
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Correct answer: B. One prolonged blast at intervals of not more than 2 minutes
Rule 35(a): one prolonged blast at intervals of not more than 2 minutes.
19.For a power-driven vessel underway manoeuvring in sight of another vessel, three short whistle blasts mean:
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Correct answer: C. I am operating astern propulsion
Rule 34(a): three short blasts mean 'I am operating astern propulsion.'
20.A vessel at anchor in fog hears a vessel approaching. Which additional whistle signal may she sound to warn of her position and the possibility of collision?
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Correct answer: D. One short, one prolonged and one short blast
Rule 35(g): a vessel at anchor may in addition sound three blasts in succession, namely one short, one prolonged and one short blast, to give warning of her position and of the possibility of collision to an approaching vessel.
21.Which of these is listed in Annex IV (Rule 37) as a visual distress signal?
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Correct answer: D. A smoke signal giving off orange-coloured smoke
Rule 37 / Annex IV: a smoke signal giving off orange-coloured smoke is a distress signal. Annex IV rockets throw red stars, and its parachute and hand flares show a red light; blue or white lights are not on the list.
22.Under Rule 32, how long does a 'prolonged blast' last?
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Correct answer: C. From four to six seconds
Rule 32(c): a prolonged blast is a blast of from four to six seconds' duration. A blast of about one second is a short blast (Rule 32(b)).
23.A vessel of 100 metres or more must carry:
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Correct answer: C. A whistle, bell, and gong
Rule 33: vessels 100m+ must have a whistle, bell, AND gong.
24.A sailing vessel underway in restricted visibility sounds:
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Correct answer: B. One prolonged followed by two short blasts at intervals of not more than 2 minutes
Rule 35(c): one prolonged followed by two short blasts at intervals of not more than 2 minutes.
25.From what length must a vessel be provided with a bell in addition to a whistle?
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Correct answer: B. 20 metres or more
Rule 33(a): a vessel of 12 m or more has a whistle; from 20 m she also has a bell; from 100 m she additionally has a gong.
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