Free practice test
PER practice test
A free PER mock exam with 45 questions. Take it against the clock and the pass mark, or read through the answers: every one is explained, so you learn from each mistake.
Reviewed by Ramon Curto, Nautical teacher at IECNPC
- 45 questions
- 90 minutes
- Pass: 32 of 45
Same format as the official theory exam: 45 questions in 90 minutes, with 32 right answers needed to pass.
This mock covers only the parts our question bank teaches: the steering and sailing rules, lights and shapes, sound signals, and IALA buoyage. The official exam also tests other subjects, so study those from the official syllabus.
These are IALACOLREG's own study questions, not official exam questions.
Take it as a timed test
90 minutes on the clock. The answers stay hidden until you finish, then you see your score against the pass mark.
Questions and answers
1.Five or more short and rapid blasts mean:
Show answer
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.
2.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)).
3.Where it is impracticable for a seaplane or WIG craft to show the lights and shapes prescribed in Part C, she must:
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Correct answer: B. Exhibit lights and shapes as closely similar as possible in characteristics and position to those prescribed
Rule 31: where compliance is impracticable, seaplanes and WIG craft shall exhibit lights and shapes as closely similar in characteristics and position as possible.
4.The day shape for a vessel constrained by draught is:
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Correct answer: C. A cylinder
Rule 28: the day shape is a cylinder.
5.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.
6.What does Rule 18 establish about priority between a vessel not under command (NUC) and a vessel restricted in her ability to manoeuvre (RAM)?
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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.
7.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.'
8.Which factor is NOT listed in Rule 6 for determining safe speed?
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Correct answer: C. Vessel's commercial schedule
Rule 6 lists visibility, traffic density, manoeuvrability, etc. Commercial schedule is never a factor in safe speed determination.
9.Local harbour authorities may make special rules that:
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Correct answer: B. Must conform as closely as possible to COLREGs
Rule 1(b) permits appropriate authorities to make special rules for connected navigable roadsteads, harbours, rivers, lakes and inland waterways; these must conform as closely as possible to COLREG.
10.So far as possible, the give-way vessel shall take action that is:
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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.
11.When is further marking decided for a danger marked by an emergency wreck marking buoy?
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Correct answer: D. Danger removed or information publicised enough
R1001 sets no fixed time: the competent authority determines further marking once the danger has been removed or its information sufficiently promulgated.
12.Rule 38 provides exemptions for:
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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.
13.A vessel of at least 12 metres restricted in her ability to manoeuvre, other than one engaged in mineclearance, displays which status lights?
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Correct answer: B. Red-white-red all-round lights vertically
Rule 27(b): RAM shows three all-round lights — red, white, red (top to bottom).
Study Rule 27: Vessels Not Under Command or Restricted in Ability to Manoeuvre
14.A vessel under sail also being propelled by her engine is classified as:
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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.
15.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.
16.Which shapes may a safe water mark have?
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Correct answer: B. Spherical, pillar or spar
A safe water mark may be spherical, pillar or spar, with red and white vertical stripes; conical and can shapes belong to lateral marks.
17.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.
18.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.
19.The second masthead light on a power-driven vessel must be:
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Correct answer: C. Abaft of and higher than the forward one
Rule 23(a)(ii): the second masthead light must be abaft of and higher than the forward one.
20.The day shape for a power-driven vessel towing astern when the tow exceeds 200 metres is:
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Correct answer: C. A diamond shape
Rule 24(a)(v): a diamond shape is shown where it can best be seen if the tow exceeds 200 metres, measured from the stern of the towing vessel to the after end of the tow.
21.How does IALA Region B differ from Region A?
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Correct answer: B. The colours are reversed — red to starboard
Region A: port-hand red, starboard-hand green. Region B: port-hand green, starboard-hand red. Interpret both in the charted conventional direction of buoyage.
22.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.
23.The Steering and Sailing Rules in Section I (Rules 4–10) apply:
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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.
24.A vessel of 50 metres or more at anchor at night shows:
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Correct answer: B. An all-round white light forward and a lower one aft
Rule 30(a): an all-round white light in the fore part and another all-round white light at a lower level near the stern.
25.A pilot vessel on duty displays at the masthead:
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Correct answer: B. White over red all-round lights
Rule 29(a): white over red all-round lights at or near the masthead.
26.On a South cardinal mark, how long does the long flash after the six quick or very quick flashes last?
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Correct answer: A. At least 2 seconds
The South cardinal light is VQ(6)+LFl 10 s or Q(6)+LFl 15 s, and the long flash lasts at least 2 s.
27.The stand-on vessel MUST take action to help avoid collision when:
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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.
28.A proper look-out must be maintained:
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Correct answer: C. At all times
Rule 5 requires every vessel to maintain a proper look-out at ALL times.
29.By day you see a spar buoy, black with a broad red horizontal band, carrying two black spheres one above the other. Which mark is it?
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Correct answer: C. Isolated danger mark
Black with one or more red horizontal bands and a topmark of two black spheres identify an isolated danger mark, set on or near a danger with navigable water around it.
30.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.
31.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.
32.If fitted, the topmark of a safe water mark is:
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Correct answer: B. A single red sphere
A safe water mark carries a single red sphere as its topmark, if fitted, on red and white vertical stripes.
33.Your power-driven vessel and another identified power-driven vessel are in sight in open water, crossing with risk of collision. She is on your starboard bow; neither is overtaking. Which duty applies to your vessel?
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Correct answer: B. Take early and substantial action to keep clear and, if circumstances admit, avoid crossing ahead
Rules 15 and 16 require your power-driven vessel to give way because the other power-driven vessel is crossing on your starboard side with risk of collision. A red sidelight alone would not establish vessel type or this duty.
34.Under the standard arrangement in Rule 25(a), a sailing vessel underway displays which navigation lights?
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Correct answer: B. Sidelights and a sternlight
Rule 25(a) prescribes sidelights and a sternlight for a sailing vessel underway. Rule 25(b) permits a combined lantern below 20 m; paragraph (c) allows a separate red-over-green pair, not with that combined lantern; paragraph (d) provides a conditional alternative below 7 m.
Study Rule 25: Sailing Vessels Underway and Vessels Under Oars
35.An isolated danger mark indicates:
Show answer
Correct answer: B. A danger with navigable water all around
An isolated danger mark is on or near a danger with navigable water around it. Consult charts and nautical publications for the extent of the danger and safe passing distance.
36.Under IALA R1001 edition 2.0, what may a special mark used as a Mobile Aid to Navigation (MAtoN) identify?
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Correct answer: A. A floating object posing a collision hazard
Edition 2.0 allows a Mobile Aid to Navigation (MAtoN) to mark a floating object that poses a collision hazard. Landfall is a safe water mark, the preferred channel a modified lateral mark, and the safe side of a danger a cardinal mark.
37.A masthead light shows over an arc of:
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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.
38.Compliance with the COLREGs:
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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.
39.For a vessel of 50m or more, the masthead light must be visible at:
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Correct answer: C. 6 nautical miles
Rule 22: masthead light of vessels 50m+ must be visible at a minimum of 6 nautical miles.
40.What light does a lit preferred-channel (modified lateral) mark show at a channel division?
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Correct answer: A. Composite group flashing Fl(2+1), in its main colour
A modified lateral mark shows composite group flashing Fl(2+1) in the main colour of the mark. White Fl(2) belongs to isolated danger marks.
41.Rule 33(a) lets the bell or gong be replaced by other equipment with the same sound characteristics, provided that:
Show answer
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.
42.Navigation lights must be displayed:
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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.
43.What body shape does an emergency wreck marking buoy have?
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Correct answer: A. Pillar or spar
R1001: the emergency wreck marking buoy is a pillar or spar buoy. Can and conical shapes are lateral shapes; spherical is used by safe water marks.
44.Two vessels navigating in or near restricted visibility are NOT in sight of one another. The crossing provisions of Rule 15:
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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.
45.An East Cardinal mark shows how many quick flashes?
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Correct answer: B. 3 flashes
White lights, when fitted: North Q or VQ; East VQ(3) 5 s or Q(3) 10 s; South VQ(6)+LFl 10 s or Q(6)+LFl 15 s; West VQ(9) 10 s or Q(9) 15 s. The long flash lasts at least 2 s.
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