Free practice test
USCG OUPV practice test
A free USCG OUPV mock exam with 50 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
- 50 questions
- 50 minutes
- Pass: 45 of 50
The official exam also has 50 questions. The clock and the pass mark here are our practice settings.
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.
The questions follow the International Rules (COLREG). The USCG exam also tests the Inland Rules, so study the differences as well.
These are IALACOLREG's own study questions, not official exam questions.
Take it as a timed test
50 minutes on the clock. The answers stay hidden until you finish, then you see your score against the pass mark.
Questions and answers
1.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.
2.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.
3.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
4.A 'vessel not under command' (NUC) is one that:
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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.
5.The day shape for a vessel engaged in fishing is:
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Correct answer: C. Two cones point to point
Rule 26: fishing vessels display two cones point to point in a vertical line as a day shape.
6.An air-cushion vessel operating in non-displacement mode must additionally show:
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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.
7.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.
8.A dredger of at least 12 metres restricted in ability to manoeuvre shows on the obstructed side:
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Correct answer: B. Two red all-round lights or balls
Rule 27(d): two red all-round lights or two balls on the obstructed side, two green or two diamonds on the clear side.
Study Rule 27: Vessels Not Under Command or Restricted in Ability to Manoeuvre
9.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.
10.According to Rule 2, departure from the COLREGs is permitted when:
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Correct answer: B. It is necessary to avoid immediate danger
Rule 2(b) allows departure from the rules when necessary to avoid immediate danger.
11.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.
12.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.
13.What colours does an isolated danger mark have?
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Correct answer: A. Black with one or more red horizontal bands
An isolated danger mark is black with one or more red horizontal bands; its topmark, if fitted, is two black spheres.
14.A power-driven vessel towing astern with tow length exceeding 200 metres, measured from her stern to the after end of the tow, shows:
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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.
15.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.
16.A 12-metre sailing yacht wants to cross a traffic lane and decides to linger inside the lane while sorting sails because she is exempt from using the main lane. What is correct?
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Correct answer: C. Incorrect because she must not impede a power-driven vessel following the traffic lane
Under Rule 10, small vessels and sailing vessels may have limited allowances, but they still shall not impede the safe passage of a power-driven vessel following a traffic lane.
17.To which vessels do the COLREGs apply?
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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.
18.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.
19.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.
20.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.
21.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.
22.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.
23.Assumptions based on scanty radar information:
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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.
24.If circumstances admit, action to avoid collision shall be:
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Correct answer: B. Positive, made in ample time
Rule 8(a) requires action in accordance with Part B and, if circumstances admit, positive action made in ample time with due regard to good seamanship.
25.Where is an isolated danger mark laid in relation to the danger it marks?
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Correct answer: A. On the danger itself, or moored over it
R1001: an isolated danger mark is erected on, or moored on or above, a danger of limited extent with navigable water all around it. It does not mark a passing distance: check charts and nautical publications for the danger's extent.
26.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.
27.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?
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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.
28.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.
29.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.
30.Both an isolated danger mark and a safe water mark have navigable water around them. What sets them apart?
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Correct answer: B. Only the safe water mark's own position is safe
A safe water mark indicates navigable water all around its own position (fairway, mid-channel or landfall). An isolated danger mark stands on or over a danger of limited extent: the water around it is navigable, but its own position is not. Both may carry a white light and a topmark, and both may be pillar-shaped.
31.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.
32.The day shape for a vessel of 12 metres or more aground is:
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Correct answer: C. Three balls vertically
Rule 30(d): three balls in a vertical line is the day shape for a vessel aground.
33.Section I of Part B (Rules 4–10) — look-out, safe speed, risk of collision, action to avoid collision — applies:
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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.
34.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.
35.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.
36.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.
37.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.
38.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.'
39.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.
40.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.
41.Under the IALA system, how is an ocean data acquisition system (ODAS) buoy marked?
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Correct answer: D. As a special mark, coloured yellow
R1001 lists ocean data acquisition systems (ODAS) among the typical uses of special marks: yellow, with a yellow X topmark and yellow light if fitted.
42.Which of these is a typical use of a special mark?
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Correct answer: A. Marking a cable or pipeline area
Special marks indicate areas or features such as cables, pipelines, spoil grounds, military exercise zones, ODAS and recreation zones. New dangers may instead be marked with lateral, cardinal, isolated-danger or emergency-wreck marks, as the competent authority determines (R1001 §3.2.2).
43.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.
44.If fitted, the topmark of an emergency wreck marking buoy is:
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Correct answer: A. An upright yellow cross
The emergency wreck marking buoy carries a standing (upright) yellow cross. The yellow X (St Andrew's cross) is the special mark topmark.
45.Which is a clear violation of the look-out requirement?
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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.
46.Which light could a lit safe water mark show?
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Correct answer: D. White, one long flash every 10 s
A safe water light, if fitted, is white: isophase, occulting, one long flash every 10 s, or Morse A. White Fl(2) marks an isolated danger; VQ(9) a West cardinal.
47.In a narrow channel, a vessel should keep to:
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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.
48.A North Cardinal mark indicates safe water lies to the:
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Correct answer: C. North of the mark
Cardinal marks indicate safe water lies on the named side: North cardinal = pass to the north.
49.The light of an emergency wreck marking buoy is:
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Correct answer: B. Alternating blue and yellow, period 3 s
The emergency wreck marking buoy shows alternating blue and yellow: 1 s blue, 0.5 s dark, 1 s yellow, 0.5 s dark — a 3 s period.
50.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.
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