COLREG practice test

Questions and answers

1. 1.Two vessels navigating in or near restricted visibility are NOT in sight of one another. The crossing provisions of Rule 15:

   A.Apply normally, since the vessels are still crossingB.Apply only to vessels over 50 mC.Do NOT apply — Rule 19 governs insteadD.Apply but with reversed priorities
   Show answer

   Correct answer: C. Do NOT apply — Rule 19 governs instead

   Rule 19 applies when vessels are not in sight. Section II rules (including crossing) only apply when vessels are in sight of each other.

   Study Rule 19: Conduct of Vessels in Restricted Visibility

2. 2.Before she is finally past and clear, an overtaking vessel's bearing changes to resemble a crossing position. What is her duty?

   A.She becomes the stand-on vessel in a crossing situationB.She remains the overtaking vessel and must keep clearC.Normal crossing rules applyD.Both vessels must alter to starboard
   Show answer

   Correct answer: B. She remains the overtaking vessel and must keep clear

   Rule 13(d): a later bearing change does not make the overtaking vessel a crossing vessel or relieve her duty until she is finally past and clear.

   Study Rule 13: Overtaking

3. 3.To which vessels do the COLREGs apply?

   A.Merchant ships over 50 m on international voyagesB.Vessels beyond territorial waters, outside any national jurisdictionC.All vessels on the high seas and connected navigable watersD.Power-driven vessels at sea; sailing craft follow local harbour rules
   Show answer

   Correct answer: C. All vessels on the high seas and connected navigable waters

   Rule 1 states the COLREGs apply to all vessels upon the high seas and in all waters connected therewith navigable by seagoing vessels.

   Study Rule 1: Application

4. 4.A vessel of at least 12 metres not under command (NUC) shows which status lights?

   A.Two all-round green lights verticallyB.Two all-round red lights verticallyC.Three all-round red lights verticallyD.Red over white over red all-round lights
   Show answer

   Correct answer: B. Two all-round red lights vertically

   Rule 27(a)(i) prescribes two all-round red lights vertically. Under Rule 27(g), vessels under 12 metres, except those engaged in diving operations, are not required to show the Rule 27 lights and shapes.

   Study Rule 27: Vessels Not Under Command or Restricted in Ability to Manoeuvre

5. 5.The Steering and Sailing Rules in Section I (Rules 4–10) apply:

   A.Only when vessels are in sight of one anotherB.Only at nightC.In any condition of visibilityD.Only in restricted visibility
   Show answer

   Correct answer: C. In any condition of visibility

   Rule 4: rules in Section I apply in any condition of visibility — clear, restricted, day or night.

   Study Rule 4: Application

6. 6.On a busy coastal night watch, the officer of the watch starts updating passage paperwork while alone on the bridge because AIS targets look stable. What is the best COLREG/STCW assessment?

   A.Acceptable, provided the radar guard zone and its alarm are switched onB.Acceptable because the helm is on autopilot and all the AIS targets look stableC.Not acceptable because the watch is no longer maintaining a proper look-outD.Acceptable as long as a continuous VHF listening watch is maintained
   Show answer

   Correct answer: C. Not acceptable because the watch is no longer maintaining a proper look-out

   Rule 5 and STCW watchkeeping principles require a proper look-out at all times. Administrative work that breaks continuous appraisal of the situation is not acceptable.

   Study Rule 5: Look-out

7. 7.Signals to attract attention must:

   A.Be chosen from the distress signals listed in Annex IV to the RulesB.Not be mistaken for any prescribed signal or aid to navigationC.Be made only by whistle, so that they are not confused with lightsD.Be made only by radio, on the distress and calling channel
   Show answer

   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.

   Study Rule 36: Signals to Attract Attention

8. 8.Two sailing vessels in sight have wind on the same side and approach with risk of collision; neither is overtaking. Which gives way?

   A.The leeward vessel gives wayB.The windward vessel gives wayC.Both vessels alter course to starboardD.The faster vessel gives way
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   Correct answer: B. The windward vessel gives way

   Rule 12(a)(ii): when both have wind on the same side, the windward vessel keeps out of the way.

   Study Rule 12: Sailing Vessels

9. 9.A masthead light shows over an arc of:

   A.135 degreesB.180 degreesC.225 degreesD.360 degrees
   Show answer

   Correct answer: C. 225 degrees

   Rule 21(a): masthead light shows over an arc of 225 degrees from dead ahead to 22.5 degrees abaft the beam on each side.

   Study Rule 21: Definitions (Lights)

10. 10.A vessel under oars at night, if she does not exhibit the lights for sailing vessels, shall:

    A.Exhibit a masthead light, sidelights and a sternlight, exactly like a power-driven vessel of her lengthB.Exhibit an all-round flashing yellow light from sunset to sunrise while under oarsC.Have ready an electric torch or lantern showing a white light, to exhibit in time to prevent collisionD.Show no lights, as vessels under oars are exempt from the lights and shapes of Part C
    Show answer

    Correct answer: C. Have ready an electric torch or lantern showing a white light, to exhibit in time to prevent collision

    Rule 25(d): a vessel under oars may exhibit the lights prescribed for sailing vessels; if she does not, she shall have ready at hand an electric torch or lighted lantern showing a white light to be exhibited in sufficient time to prevent collision.

    Study Rule 25: Sailing Vessels Underway and Vessels Under Oars

11. 11.A give-way vessel makes one small course change, sees little effect on CPA, and then waits. What is the best critique?

    A.Correct, because any visible alteration satisfies Rule 8B.Incorrect, because avoiding action should be substantial and then monitored until effectiveC.Correct, because the stand-on vessel must now solve the situationD.Incorrect only if the change increased fuel use
    Show answer

    Correct answer: B. Incorrect, because avoiding action should be substantial and then monitored until effective

    Rule 8 requires positive action in ample time and follow-up monitoring. A token alteration that does not open the situation is not enough.

    Study Rule 8: Action to Avoid Collision

12. 12.What does Rule 18 establish about priority between a vessel not under command (NUC) and a vessel restricted in her ability to manoeuvre (RAM)?

    A.NUC always has priority over RAMB.RAM always has priority over NUCC.Rule 18 establishes no priority order between NUC and RAMD.Both must always give way to sailing vessels
    Show answer

    Correct answer: C. Rule 18 establishes no priority order between NUC and RAM

    Rule 18(b) requires a sailing vessel underway to keep out of the way of NUC, RAM and vessels engaged in fishing. Rule 18 does not rank NUC above RAM; there is no complete vessel priority ladder.

    Study Rule 18: Responsibilities Between Vessels

13. 13.From what length must a vessel be provided with a bell in addition to a whistle?

    A.12 metres or moreB.20 metres or moreC.50 metres or moreD.100 metres or more
    Show answer

    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.

    Study Rule 33: Equipment for Sound Signals

14. 14.In a narrow channel, a vessel should keep to:

    A.The centre line of the channel, so as to keep well clear of both banksB.As near the outer limit on her port side as is safe and practicableC.As near the outer limit on her starboard side as is safe and practicableD.Whichever side of the channel offers the deeper water and the most room to manoeuvre
    Show answer

    Correct answer: C. As near the outer limit on her starboard side as is safe and practicable

    Rule 9(a): a vessel shall keep as near to the outer limit on her starboard side as is safe and practicable.

    Study Rule 9: Narrow Channels

15. 15.A vessel may properly use an inshore traffic zone when:

    A.It wants a shorter route and the adjacent lane is crowded with slow trafficB.It is bound to or from a port, offshore installation, or station within the zoneC.It is over 20 metres and wishes to keep clear of the heavier traffic in the laneD.It is overtaking a slower vessel and the lane offers too little room to pass
    Show answer

    Correct answer: B. It is bound to or from a port, offshore installation, or station within the zone

    Rule 10 allows inshore-zone use in specific cases, including vessels bound to or from a port, offshore installation or station within the zone, and for certain small craft, sailing vessels, fishing vessels or immediate danger.

    Study Rule 10: Traffic Separation Schemes

16. 16.Navigation lights must be displayed:

    A.From sunset to sunrise, and by day only when anchored in or near a fairwayB.From sunset to sunrise and, if carried, also by day in restricted visibilityC.From one hour before sunset until one hour after sunrise, whatever the visibilityD.Only when other vessels are nearby, by day or by night
    Show answer

    Correct answer: B. From sunset to sunrise and, if carried, also by day in restricted visibility

    Rule 20(b) requires prescribed lights from sunset to sunrise. Under 20(c), those lights, if carried, must also be shown by day in restricted visibility and may be shown in other circumstances when deemed necessary.

    Study Rule 20: Application (Lights)

17. 17.An air-cushion vessel operating in non-displacement mode must additionally show:

    A.Two all-round red lights in a vertical lineB.An all-round flashing yellow lightC.An all-round flashing blue lightD.Three masthead lights in a vertical line
    Show answer

    Correct answer: B. An all-round flashing yellow light

    Rule 23(b): an air-cushion vessel in non-displacement mode shows an all-round flashing yellow light.

    Study Rule 23: Power-driven Vessels Underway

18. 18.A vessel under sail also being propelled by her engine is classified as:

    A.A sailing vesselB.A power-driven vesselC.A vessel restricted in ability to manoeuvreD.A vessel not under command
    Show answer

    Correct answer: B. A power-driven vessel

    Rule 3(c): a sailing vessel means any vessel under sail provided that propelling machinery, if fitted, is not being used.

    Study Rule 3: General Definitions

19. 19.In the COLREG, what does the word 'whistle' mean (Rule 32)?

    A.Any sound-signalling appliance that can give the prescribed blasts and meets Annex IIIB.Only a mouth-blown whistle kept with the life-saving appliances on boardC.Any horn or siren that can give the prescribed blasts, whatever its sound level and rangeD.Only a steam or compressed-air whistle mounted high on the funnel or mast
    Show answer

    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.

    Study Rule 32: Definitions (Sound Signals)

20. 20.Which is a clear violation of the look-out requirement?

    A.Using binoculars to identify distant lights during the night watchB.Assigning the look-out person administrative paperwork during the watchC.Using radar and ARPA to supplement the visual look-out in clear weatherD.Posting an additional look-out on the bow in restricted visibility
    Show answer

    Correct answer: B. Assigning the look-out person administrative paperwork during the watch

    A proper look-out must be able to give full attention to the task. Assigning unrelated duties that distract the watch violates the rule.

    Study Rule 5: Look-out

21. 21.So far as possible, the give-way vessel shall take action that is:

    A.Minimal and gradualB.Early and substantialC.Only a speed reductionD.Directed by the stand-on vessel
    Show answer

    Correct answer: B. Early and substantial

    Rule 16 requires every vessel directed to keep out of the way, so far as possible, to take early and substantial action to keep well clear.

    Study Rule 16: Action by Give-way Vessel

22. 22.In thick fog another vessel is detected only by ARPA and is not in sight. Its bearing is steady and range is closing fast. Which rule governs the avoiding action?

    A.Rule 15 — crossing situation, give way as normalB.Rule 14 — head-on, alter to starboard as in clear weatherC.Rule 19 — restricted visibility, because vessels are not in sightD.Rule 13 — overtaking, because the bearing is steady
    Show answer

    Correct answer: C. Rule 19 — restricted visibility, because vessels are not in sight

    Rule 11 restricts Section II (including crossing, head-on and overtaking) to vessels in sight of one another. A target detected only on radar is not 'in sight'; Rule 19 governs instead.

    Study Rule 11: Application

23. 23.A 'vessel not under command' (NUC) is one that:

    A.From the nature of her work is restricted in her ability to manoeuvre as required and so cannot keep out of the wayB.Because of her draught in relation to the available depth of water is severely restricted in deviating from her courseC.Through exceptional circumstances cannot manoeuvre as required and therefore cannot keep out of another vessel's wayD.Is fishing with nets, lines or trawls that restrict her manoeuvrability and so cannot keep out of the way
    Show answer

    Correct answer: C. Through exceptional circumstances cannot manoeuvre as required and therefore cannot keep out of another vessel's way

    Rule 3(f) requires both inability to manoeuvre as required because of exceptional circumstances and consequent inability to keep out of another vessel's way.

    Study Rule 3: General Definitions

24. 24.Which sound signal is listed in Annex IV (Rule 37) as a distress signal?

    A.At least five short, rapid blasts on the ship's whistleB.A continuous sounding with any fog-signalling apparatusC.One short, one prolonged and one short blastD.Four short blasts repeated every two minutes
    Show answer

    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.

    Study Rule 37: Distress Signals

25. 25.Two power-driven vessels in sight meet on reciprocal or nearly reciprocal courses with risk of collision. Under Rule 14, each shall:

    A.Alter course to portB.Alter course to starboardC.Reduce speedD.Sound one prolonged blast
    Show answer

    Correct answer: B. Alter course to starboard

    Rule 14(a): each shall alter course to starboard so that each passes on the port side of the other.

    Study Rule 14: Head-on Situation

26. 26.For vessels with operational radar, safe speed must additionally consider:

    A.The commercial value of the cargo being carriedB.Characteristics and limitations of radar equipmentC.The number of crew members on the bridge watchD.The vessel's insurance and classification requirements
    Show answer

    Correct answer: B. Characteristics and limitations of radar equipment

    Rule 6(b) applies to vessels with operational radar and requires consideration of its characteristics, efficiency and limitations, among other radar-related factors.

    Study Rule 6: Safe Speed

27. 27.Risk of collision is deemed to exist when:

    A.The compass bearing of an approaching vessel does not appreciably changeB.Two vessels are within 5 nautical milesC.A vessel is detected on radarD.Another vessel is visible
    Show answer

    Correct answer: A. The compass bearing of an approaching vessel does not appreciably change

    Rule 7(d)(i): risk shall be deemed to exist if the compass bearing of an approaching vessel does not appreciably change.

    Study Rule 7: Risk of Collision

28. 28.In restricted visibility, a vessel aground gives the anchor bell signal (and the gong if required). What must she add?

    A.One short, one prolonged and one short blast after each bellB.Two prolonged blasts every 2 minutes in place of the gongC.Three separate, distinct bell strokes just before and after the ringingD.Five short and rapid blasts whenever another vessel is heard nearby in the fog
    Show answer

    Correct answer: C. Three separate, distinct bell strokes just before and after the ringing

    Rule 35(h): a vessel aground gives the bell signal and, if required, the gong signal of Rule 35(g), and in addition three separate and distinct strokes on the bell immediately before and after the rapid ringing of the bell. She may also sound an appropriate whistle signal.

    Study Rule 35: Sound Signals in Restricted Visibility

29. 29.Assumptions based on scanty radar information:

    A.Are acceptable if AIS confirms the targetB.Shall NOT be madeC.May be made by dayD.Are permitted
    Show answer

    Correct answer: B. Shall NOT be made

    Rule 7(c): assumptions shall not be made on the basis of scanty information, especially scanty radar information.

    Study Rule 7: Risk of Collision

30. 30.According to Rule 2, departure from the COLREGs is permitted when:

    A.The master decides the rules are impracticalB.It is necessary to avoid immediate dangerC.Visibility is restrictedD.The vessel is in a traffic separation scheme
    Show answer

    Correct answer: B. It is necessary to avoid immediate danger

    Rule 2(b) allows departure from the rules when necessary to avoid immediate danger.

    Study Rule 2: Responsibility

31. 31.For a vessel of 50m or more, the masthead light must be visible at:

    A.3 nautical milesB.5 nautical milesC.6 nautical milesD.8 nautical miles
    Show answer

    Correct answer: C. 6 nautical miles

    Rule 22: masthead light of vessels 50m+ must be visible at a minimum of 6 nautical miles.

    Study Rule 22: Visibility of Lights

32. 32.Compliance with the COLREGs:

    A.Relieves the stand-on vessel of all liability once she has kept her courseB.Does not exonerate a vessel from the consequences of neglecting good seamanshipC.Is compulsory only for vessels over 12 metres; smaller craft may rely on seamanshipD.Is optional in territorial waters where the coastal state's own rules prevail
    Show answer

    Correct answer: B. Does not exonerate a vessel from the consequences of neglecting good seamanship

    Rule 2(a) states nothing in the rules exonerates any vessel from the consequences of neglecting good seamanship.

    Study Rule 2: Responsibility

33. 33.Section I of Part B (Rules 4–10) — look-out, safe speed, risk of collision, action to avoid collision — applies:

    A.Only when other vessels are in sightB.In any condition of visibility, day or nightC.Only in restricted visibilityD.Only when transiting a traffic separation scheme
    Show answer

    Correct answer: B. In any condition of visibility, day or night

    Rule 4 applies Section I in any condition of visibility. Rule 11 limits Section II to vessels in sight of one another. Rule 19 applies to vessels not in sight when navigating in or near restricted visibility.

    Study Rule 4: Application

34. 34.A vessel nearing a bend in a channel sounds one prolonged blast. How must an approaching vessel that hears it from behind the bend answer?

    A.With five short and rapid blastsB.With two short blastsC.With one short blastD.With one prolonged blast
    Show answer

    Correct answer: D. With one prolonged blast

    Rule 34(e): the signal shall be answered with a prolonged blast by any approaching vessel that may be within hearing around the bend or behind the intervening obstruction.

    Study Rule 34: Manoeuvring and Warning Signals

35. 35.At night a vessel engaged in fishing other than trawling has outlying gear extending more than 150 metres horizontally to starboard. Which extra light is required?

    A.An all-round white light in the direction of the outlying gearB.An all-round red light in the direction of the outlying gearC.A green light over a white light on the side of the gearD.Two all-round white lights in the direction of the outlying gear
    Show answer

    Correct answer: A. An all-round white light in the direction of the outlying gear

    Rule 26(c)(ii) requires an additional all-round white light toward outlying gear extending more than 150 metres for fishing other than trawling. The corresponding day shape is a cone with apex upward.

    Study Rule 26: Fishing Vessels

36. 36.In patchy fog with fishing activity ahead, the master wants to maintain schedule because radar is working well. Which factor should drive the speed decision?

    A.The ETA at the next waypoint and the charter-party schedule commitmentsB.The vessel's ability to take effective action and stop within an appropriate distanceC.The radar's ability to detect targets, which removes the need to slow downD.The other vessels' likely obligation to keep clear of her once they detect her on radar
    Show answer

    Correct answer: B. The vessel's ability to take effective action and stop within an appropriate distance

    Rule 6 is about safe speed in the actual circumstances. Schedule pressure is irrelevant compared with stopping distance, manoeuvrability, visibility and traffic density.

    Study Rule 6: Safe Speed

37. 37.The stand-on vessel MUST take action to help avoid collision when:

    A.The give-way vessel sounds one short blast while altering to starboardB.Collision cannot be avoided by the give-way vessel acting aloneC.A third vessel enters the area and the situation becomes complexD.Visibility becomes restricted during the encounter
    Show answer

    Correct answer: B. Collision cannot be avoided by the give-way vessel acting alone

    Rule 17(b): once so close that the give-way vessel alone cannot avoid collision, the stand-on vessel shall take action that best helps avoid it. Rule 17(a)(ii) separately permits earlier action when the give-way vessel is not taking appropriate action.

    Study Rule 17: Action by Stand-on Vessel

38. 38.Two power-driven vessels in sight are crossing with risk of collision. The give-way vessel has the other on her:

    A.Port sideB.Starboard sideC.Port quarter, abaft the beamD.Right ahead
    Show answer

    Correct answer: B. Starboard side

    Rule 15: the vessel which has the other on her starboard side shall keep out of the way.

    Study Rule 15: Crossing Situation

39. 39.Rule 38 provides exemptions for:

    A.Recreational craft under 12 metres, from the light and sound signal requirementsB.Specified light and sound requirements for eligible older vessels complying with the 1960 rulesC.Warships and naval auxiliaries, from the positioning of lights and shapes at all timesD.Fishing vessels operating in national waters, from the sound signal appliances required by Annex III
    Show answer

    Correct answer: B. Specified light and sound requirements for eligible older vessels complying with the 1960 rules

    Rule 38 concerns vessels complying with the 1960 Collision Regulations whose keels were laid, or which were at a corresponding construction stage, before 15 July 1977. It grants only listed exemptions, some permanent and others for transition periods; navigation duties remain.

    Study Rule 38: Exemptions

40. 40.A power-driven vessel towing astern with tow length exceeding 200 metres, measured from her stern to the after end of the tow, shows:

    A.Two masthead lights in a vertical lineB.Three masthead lights in a horizontal lineC.Three masthead lights in a vertical lineD.Four masthead lights in a vertical line
    Show answer

    Correct answer: C. Three masthead lights in a vertical line

    Rule 24(a)(i): three masthead lights in a vertical line when the tow exceeds 200 metres.

    Study Rule 24: Towing and Pushing

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Read the rules behind the questions

• Study Rule 5: Look-out
• Study Rule 7: Risk of Collision
• Study Rule 13: Overtaking
• Study Rule 15: Crossing Situation
• Study Rule 18: Responsibilities Between Vessels
• Study Rule 19: Conduct of Vessels in Restricted Visibility