Free practice test
IALA buoyage practice test
40 questions on the IALA buoyage system: lateral marks in Regions A and B, cardinal marks, isolated danger, safe water, special and emergency wreck marks. Every answer is explained.
Reviewed by Ramon Curto, Nautical teacher at IECNPC
- 40 questions
- 35 minutes
- Pass: 32 of 40
To pass you need 80% right: the same standard as our timed subject exams.
These are IALACOLREG's own study questions, not official exam questions.
Take it as a timed test
35 minutes on the clock. The answers stay hidden until you finish, then you see your score against the pass mark.
Questions and answers
1.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.
2.Which of these may be fitted to an emergency wreck marking buoy?
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Correct answer: C. An AIS transponder
R1001: an emergency wreck marking buoy may carry an AIS transponder and, if fitted, a RACON. EPIRBs, NAVTEX and DSC belong to the GMDSS equipment of ships and shore stations, not to buoyage.
3.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.
4.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.
5.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.
6.Safe water marks are used as:
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Correct answer: B. Fairway or mid-channel marks
Safe water marks are used as fairway, mid-channel, or landfall marks.
7.At a channel division in IALA Region A, the preferred channel is to port. Which mark shows this?
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Correct answer: C. Green with one broad red band; green cone, point up
A modified lateral mark keeps its main colour and topmark and adds one broad band of the opposite colour. For a preferred channel to port in Region A it is a modified starboard-hand mark: green with a broad red band and a green cone, point up. Its light, if fitted, is Fl(2+1) green.
8.Once an emergency wreck marking buoy has been laid, who determines any further marking of the danger?
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Correct answer: C. The competent authority
R1001: the competent authority determines further marking once the danger has been removed or its information sufficiently promulgated.
9.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.
10.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.
11.What colour of light does a lit port-hand lateral mark show in IALA Region A?
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Correct answer: C. Red, the same colour as the mark
A lateral mark's light, when fitted, has the same colour as the mark: red for a Region A port-hand mark, green for a starboard-hand mark.
12.At night in IALA Region B, what light does a lit port-hand lateral mark show?
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Correct answer: D. A green light
In Region B the port-hand mark is green, and its light, when fitted, is green too; red marks and red lights are on the starboard side.
13.Special marks are coloured:
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Correct answer: C. Yellow
Special marks are yellow, indicating special areas like military zones, cables, or pipelines.
14.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.
15.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.
16.If an isolated danger mark is lit, what light does it show?
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Correct answer: C. White, group flashing Fl(2)
When fitted, the isolated danger light is white, group flashing (2): two flashes repeated. A long flash every 10 s belongs to safe water marks.
17.Following the conventional direction of buoyage in IALA Region B, which mark do you leave to starboard?
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Correct answer: A. A red, usually conical mark
Region B reverses the lateral colours: the starboard-hand mark is red and usually conical (nun), the port-hand mark green and usually can-shaped.
18.Safe water marks have:
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Correct answer: A. Red and white vertical stripes
Safe water marks are red and white vertical stripes, indicating navigable water all around.
19.What are the colours of a South cardinal mark?
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Correct answer: B. Yellow above black
South cardinal: yellow above black, with two black cones pointing down. North is black above yellow; East is black-yellow-black; West is yellow-black-yellow.
20.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.
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.If an emergency wreck marking buoy carries a RACON, which Morse letter does it transmit?
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Correct answer: D. D (dash–dot–dot)
The RACON on an emergency wreck marking buoy, if fitted, is coded Morse D (dash–dot–dot).
23.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.
24.If fitted, the topmark of a special mark is:
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Correct answer: B. A yellow X-shape (cross)
Special marks have a yellow X-shaped (St. Andrew's cross) topmark. (if fitted).
25.You are entering a river where the chart shows the conventional direction of buoyage is upstream from the sea entrance. What should determine whether a lateral mark is port-hand or starboard-hand?
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Correct answer: C. The charted conventional direction of buoyage
Lateral marks are interpreted in the conventional direction of buoyage. The chart, not guesswork, determines which side is port-hand and which is starboard-hand.
26.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.
27.A lit safe water mark may show which Morse code letter?
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Correct answer: A. A (dot–dash), in white
One of the safe water light options is Morse A (dot–dash), always in white. Morse D is the RACON code of the emergency wreck marking buoy.
28.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).
29.An isolated danger mark indicates:
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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.
30.Which white light characteristic belongs to an East cardinal mark?
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Correct answer: B. VQ(3) every 5 s or Q(3) every 10 s
East cardinal: VQ(3) 5 s or Q(3) 10 s — three flashes, like 3 o'clock. West uses 9 flashes, South 6 plus a long flash, North continuous flashing.
31.If fitted, the topmark of an East cardinal mark is:
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Correct answer: C. Two black cones, base to base
East cardinal: two black cones base to base, black-yellow-black bands, and a white light (if fitted) of 3 quick or very quick flashes.
32.How do special marks differ between IALA Region A and Region B?
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Correct answer: B. No difference; only lateral marks change
Only the lateral marks (and the preferred-channel marks derived from them) swap colours between Region A and Region B. Special marks are yellow, with a yellow X topmark and a yellow light if fitted, in both regions.
33.A cardinal mark and an isolated danger mark can both warn of a danger. What does the cardinal mark tell you that the isolated danger mark does not?
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Correct answer: D. The side of the danger where the safe water lies
A cardinal mark names the quadrant in which the safe water lies, so you pass on its named side. An isolated danger mark instead shows a danger of limited extent with navigable water all around it. Neither gives a passing distance: take that from charts and nautical publications.
34.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.
35.What does a special mark by itself tell you?
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Correct answer: D. Charts and publications describe its area
A special mark indicates an area or feature whose nature is described in charts and nautical publications; the mark itself gives no passing side. Navigable water all around is the meaning of a safe water mark.
36.If fitted, the topmark of an isolated danger mark is:
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Correct answer: B. Two black spheres vertically
Isolated danger marks have two black spheres (balls) as topmark. (if fitted).
37.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.
38.You sight a cardinal mark with both cones pointing down and a light showing six quick flashes followed by one long flash. What is the safe action?
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Correct answer: C. Pass south of the mark
Two cones down and the 6+1 light rhythm identify a South Cardinal mark, meaning the safe water lies to the south of the mark.
39.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.
40.Emergency wreck marking buoys are used for:
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Correct answer: B. Marking new dangers, including newly discovered wrecks
The emergency wreck marking buoy marks new dangers, including newly discovered wrecks. The competent authority determines further marking once the danger is removed or its information has been sufficiently promulgated.
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