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HK Coxswain Grade 3 study materials
HK Coxswain Grade 3 study resources

HK Coxswain Grade 3 practice questions

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Question 1Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

Under the International Regulations for Preventing Collisions at Sea, which light configuration identifies a vessel restricted in her ability to manoeuvre, other than a minesweeper, when making way through the water?

  1. Red over white over red, with masthead, sidelights and sternlight when making way Correct answer.
  2. Green over white over green, with a single all-round white light
  3. Red over red over red, with no sidelights at any time
  4. Yellow over yellow, with two all-round red lights

Explanation

A vessel restricted in her ability to manoeuvre shows three all-round lights in a vertical line, red over white over red, plus masthead light or lights, sidelights and sternlight when making way. The same basic arrangement is shown at anchor without the running lights. The red-white-red sequence is the diagnostic feature candidates must recognise in the harbour.

Question 2Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

In Hong Kong waters, the International Code flag 'A' (Alpha) flown by a vessel indicates which of the following?

  1. The vessel is loading dangerous goods
  2. The vessel has a diver down and must be kept well clear Correct answer.
  3. The vessel is under quarantine
  4. The vessel is aground and requests immediate assistance

Explanation

Flag Alpha means the vessel has a diver down and other vessels should keep well clear at slow speed. This is a common sight around Hong Kong during underwater inspection and repair work. Coxswains must recognise it and reduce wash accordingly.

Question 3Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

Which charted symbol indicates a lateral mark indicating the port side of a channel when proceeding in the direction of buoyage?

  1. A can-shaped mark, red in IALA region A Correct answer.
  2. A conical mark, red in IALA region A
  3. A spherical mark with red and white vertical stripes
  4. A can-shaped mark, green in IALA region A

Explanation

In IALA region A, which includes Hong Kong, port-hand marks are red and can-shaped. Starboard-hand marks are green and conical. A spherical red-and-white mark is a safe-water mark, not a lateral mark.

Question 4Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

What does a charted magenta arrow with feathers on a nautical chart indicate?

  1. The limits of a prohibited area
  2. The direction and rate of the tidal stream at that position Correct answer.
  3. A recommended anchorage sector
  4. The direction of the prevailing wind

Explanation

Magenta arrows with feathers on charts show tidal stream direction and rate, usually with figures for spring and neap rates. They help the coxswain plan a passage with or against the current. Wind roses use a different symbol.

Question 5Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain sights a lighthouse flashing every 6 seconds. On the chart the light is described as 'Fl(2) 10s'. What does the chart description mean?

  1. A single flash lasting 10 seconds
  2. Two lights each with a 10-second period
  3. Ten flashes every 2 seconds
  4. Two flashes every 10 seconds Correct answer.

Explanation

The notation Fl(2) 10s means a group of two flashes repeated every 10 seconds. The number in brackets gives the number of flashes in the group, and the figure after gives the total period. This allows the coxswain to identify the light positively at night.

Question 6Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

Which statement correctly describes the meaning of a 'leading line' marked on a chart?

  1. A line joining points of equal depth
  2. A transit formed by two charted objects which, kept in line, indicates a safe course Correct answer.
  3. A line marking the edge of a traffic separation scheme
  4. The boundary between two charted depths

Explanation

A leading line is a transit, usually drawn as a dashed line between two structures, showing the safe direction of travel when the marks are kept in line. It is used to steer a channel accurately. Depth contours and traffic boundaries use different symbology.

Question 7Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

Which of the following is the correct action for a coxswain on seeing a vessel displaying two black balls in a vertical line by day?

  1. Treat the vessel as a pilot vessel and follow her
  2. Treat the vessel as a vessel constrained by her draught and pass at speed
  3. Treat the vessel as not under command and keep clear Correct answer.
  4. Treat the vessel as a fishing vessel and pass close astern

Explanation

Two black balls in a vertical line indicate a vessel not under command. Such a vessel cannot manoeuvre as required and other vessels must keep well clear. Recognising this shape by day is as important as recognising the red lights at night.

Question 8Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is asked to fix the vessel's position using a hand-bearing compass. Which three objects give the most reliable fix in Hong Kong harbour?

  1. A single floating buoy and the vessel's estimated speed
  2. The direction of the wind and the nearest shoreline
  3. Two charted landmarks with a known angle between them and a depth sounding Correct answer.
  4. The sun's bearing and the vessel's compass heading

Explanation

A reliable fix comes from bearings to two well-defined charted objects combined with a depth, giving a position that can be cross-checked. Buoys may move or be unlit, and single observations do not give a position. Depth confirms the fix and detects errors.

Question 9Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

On a Hong Kong chart, a depth marked '5₄' in a drying area indicates what?

  1. A depth of 5.4 metres below chart datum
  2. A depth of 5 metres at high water and 4 metres at low water
  3. A rock with 5 metres clearance and 4 metres tidal range
  4. A depth of 5 metres with 4 metres of drying height Correct answer.

Explanation

In drying areas, the large figure gives the drying height and the subscript figure gives the depth below chart datum. The notation is used to show both the shallowest water and the amount exposed at low water. Coxswains must read both figures when planning a shallow-water passage.

Question 10Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is planning a passage from Victoria Harbour to Sai Kung. Which charted feature most directly limits the vessel's safe speed through the harbour approaches?

  1. The colour of the buoys marking the channel
  2. The presence of a lighthouse on the headland
  3. The charted depth contours and the location of the traffic separation scheme Correct answer.
  4. The number of charted anchorages

Explanation

Depth contours determine the available water, and the traffic separation scheme dictates the direction and lane the vessel must follow. Together they control how fast and where the vessel may safely proceed. Buoy colour and lighthouse presence do not limit speed directly.

Question 11Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

Which statement about the International Regulations for Preventing Collisions at Sea, Rule 9, is correct for a coxswain in a narrow channel?

  1. A vessel may anchor in a narrow channel to wait for a berth
  2. A vessel must always keep to the port side of a narrow channel
  3. A vessel under 20 metres may keep to the starboard side but may cross the channel freely
  4. A vessel proceeding along the course of a narrow channel must keep as near to the outer limit on her starboard side as is safe Correct answer.

Explanation

Rule 9 requires a vessel proceeding along a narrow channel to keep as near to the outer limit on her starboard side as is safe and practicable. Crossing the channel should be avoided where it impedes other traffic. Anchoring in a narrow channel is prohibited except in an emergency.

Question 12Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is using a GPS receiver and a paper chart. Which practice best guards against a gross position error?

  1. Relying solely on the GPS latitude and longitude
  2. Plotting the GPS position and cross-checking it against bearings to two charted objects Correct answer.
  3. Ignoring the chart and steering by the buoys alone
  4. Using the GPS only when visibility is poor

Explanation

Plotting the GPS fix and cross-checking it against visual bearings to two charted objects gives an independent confirmation. If the two disagree, the coxswain can detect a datum, offset or receiver error. Single-source navigation is poor practice.

Question 13Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

What is the purpose of a traffic separation scheme in Hong Kong waters?

  1. To mark the boundary of a military exercise area
  2. To reserve an area for fishing vessels only
  3. To separate opposing streams of traffic by designated lanes and a separation zone Correct answer.
  4. To indicate the limits of the harbour speed limit

Explanation

A traffic separation scheme uses lanes and a separation zone to keep opposing streams of traffic apart, reducing head-on risk. Vessels must follow the lane direction and cross at right angles where possible. Fishing areas and speed limits are shown separately.

Question 14Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain observes a green conical buoy on the starboard bow while heading up a channel. What does this indicate?

  1. The vessel is on the port side of the channel and should move to starboard
  2. The buoy marks a wreck to be passed on the port side
  3. The vessel is correctly on the starboard side of the channel Correct answer.
  4. The buoy marks a safe-water mark at the channel entrance

Explanation

In IALA region A, a green conical mark is a starboard-hand mark. Seeing it on the starboard bow while heading up the channel confirms the vessel is on the correct side. A port-hand mark would be red and can-shaped.

Question 15Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

Which factor most affects the height of tide at a secondary port in Hong Kong compared with the standard port?

  1. The difference in tidal constants and the local topography Correct answer.
  2. The colour of the chart covering the area
  3. The depth of water at the secondary port
  4. The distance of the secondary port from the standard port

Explanation

Secondary port tide predictions are derived from the standard port by applying differences in tidal constants and accounting for local topography. Distance alone does not determine the difference. Depth and chart colour are irrelevant to tidal prediction.

Question 16Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is approaching a harbour entrance at night and sees a light showing alternating white and red sectors. What is the correct interpretation?

  1. The red sector marks the safe channel and the white sector marks danger
  2. The light is a buoy marking a wreck
  3. The red sector warns of danger and the white sector marks safe water Correct answer.
  4. Both sectors indicate the same safe water

Explanation

Sector lights use colour to indicate safe and unsafe water. The white sector usually marks the safe approach, and red warns of danger such as shoals or rocks. The coxswain should keep the vessel within the white sector.

Question 17Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

What does a charted 'no anchoring' symbol, usually a black anchor with a red line through it, indicate?

  1. The area has no holding ground
  2. The area is reserved for anchoring of large vessels
  3. Anchoring is permitted only in an emergency
  4. Anchoring is prohibited in that area Correct answer.

Explanation

A crossed anchor indicates that anchoring is prohibited, often because of cables, pipelines or a designated fairway. A coxswain must not anchor there even temporarily. Holding ground quality is shown by other chart notes.

Question 18Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is planning a night passage across the harbour. Which publication should be consulted for the latest notice of a changed buoy position?

  1. The tide tables for the day
  2. The vessel's own logbook
  3. The latest Notices to Mariners affecting the chart Correct answer.
  4. The current chart edition only

Explanation

Notices to Mariners are the official means of advising changes to charts, lights and buoyage between editions. The coxswain must check the latest notices and correct the chart before the passage. Tide tables and logbooks do not report chart changes.

Question 19Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

Which statement best describes the effect of squat on a small vessel proceeding at speed in shallow water?

  1. The vessel's stability improves at high speed
  2. The vessel rises bodily in the water and turns more easily
  3. The vessel's draft decreases and speed increases
  4. The vessel sinks bodily and may become harder to steer Correct answer.

Explanation

Squat is the bodily sinking of a vessel caused by the flow of water past the hull, and it is more pronounced in shallow water. Steering can become sluggish and the vessel may touch bottom. Coxswains should reduce speed in shallow or confined water.

Question 20Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain sees a vessel displaying a black cylinder shape. What does this indicate?

  1. A vessel engaged in fishing
  2. A vessel not under command
  3. A vessel constrained by her draught Correct answer.
  4. A vessel aground

Explanation

A single black cylinder is the day shape for a vessel constrained by her draught. Such a vessel may have limited ability to alter course and other vessels should give her room. The shape must not be confused with the two balls of a not-under-command vessel.

Question 21Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is fixing position by a running fix. What is the essential requirement for this method?

  1. Two bearings taken at the same instant
  2. Two bearings of the same object taken at different times with the run between them Correct answer.
  3. A single bearing and a depth sounding
  4. A bearing of the sun and a compass heading

Explanation

A running fix uses two bearings of the same object taken at different times, with the vessel's run between the observations transferred to the chart. The accuracy depends on knowing the course and speed over the interval. Two simultaneous bearings give a simple fix, not a running fix.

Question 22Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is navigating a narrow channel at night where several lights are visible. Which feature should be used to positively identify the correct leading light?

  1. The height of the light above the water
  2. The light's characteristic, such as its flash pattern and period, matched to the chart Correct answer.
  3. The colour of the light alone
  4. The brightness of the light compared with others

Explanation

Lights are positively identified by their characteristic, the flash pattern and period printed on the chart. Colour alone may be shared by several lights, and brightness and height are unreliable at a distance. Matching the characteristic prevents a wrong-light error.

Question 23Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is planning a passage that crosses a traffic separation scheme. According to the Collision Regulations, how should the crossing be made?

  1. At as small an angle to the lane direction as possible
  2. By following the lane in the wrong direction until a gap appears
  3. As nearly as practicable at right angles to the general direction of traffic flow Correct answer.
  4. By stopping in the separation zone to wait for a gap

Explanation

A vessel crossing a traffic separation scheme must cross as nearly as practicable at right angles to the general direction of traffic flow. This minimises the time spent in the lane and reduces collision risk. Stopping in the separation zone is prohibited.

Question 24Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is using a chart with a stated horizontal datum that differs from the GPS datum. What is the correct action?

  1. Apply the chart's datum shift to GPS positions before plotting Correct answer.
  2. Ignore the difference because GPS is always accurate
  3. Change the GPS datum only when visibility is poor
  4. Use the chart without correction and rely on visual bearings only

Explanation

If the chart datum differs from the GPS datum, a datum shift must be applied to GPS positions before plotting. Failure to do so can put the plotted position several hundred metres from the true position. Visual bearings can cross-check the corrected position.

Question 25Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain observes that a charted light listed as 'Oc R 5s' is showing a steady red light with no occultations. What is the most likely explanation?

  1. The chart is correct and the light is faulty
  2. The light has been changed to a fixed red light and a Notice to Mariners should be checked Correct answer.
  3. The coxswain is looking at the wrong light
  4. The light is obscured by a passing vessel

Explanation

An occulting light should show regular periods of darkness. A steady red light where an occulting light is charted suggests a change in the light or a different light altogether, and the coxswain should check the latest Notices to Mariners. Relying on the chart alone could lead to a wrong identification.

Question 26Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is entering Hong Kong's Western Harbour and sees a charted buoy with red and white vertical stripes and a red topmark. What does this buoy most likely mark?

  1. The safe centre of the navigable channel
  2. A hazard such as a wreck or rock awash
  3. The port-hand limit of the channel
  4. A fairway or channel junction where the main channel is crossed Correct answer.

Explanation

Red and white vertical stripes identify a safe water mark, which in IALA Region A indicates navigable water, often the centre of a channel or a fairway junction or landfall. It is not a lateral mark, so it does not define the port or starboard edge of the channel.

Question 27Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

While planning a passage across Hong Kong waters, a coxswain notes that the chart shows a 'P' beside a light characteristic. What does the 'P' indicate about the light?

  1. The light may be irregular or unreliable in its timing Correct answer.
  2. The light is a private light not maintained by the authority
  3. The light is powered by solar panels
  4. The light operates only when a vessel requests it

Explanation

In light lists and on charts, a light marked with 'P' or described as 'irregular' may not keep exact timing, so a coxswain should not rely on it for precise timing. This is a caution when using lights for position fixing at night.

Question 28Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is fixing position in Victoria Harbour using two charted landmarks and a hand-bearing compass. The two bearings intersect at a very small angle. What is the main problem with this fix?

  1. The fix is invalid because three bearings are always required
  2. The fix will be accurate because small angles reduce error
  3. The fix will be inaccurate because the angle of cut is too small Correct answer.
  4. The fix cannot be plotted because the bearings are reciprocal

Explanation

A position fix is most reliable when the position lines cross at angles close to 90 degrees. A small angle of cut magnifies any bearing error, producing a large uncertainty in the plotted position, so a third object should be chosen to improve the geometry.

Question 29Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is proceeding eastward through the Tathong Channel at night and sees a vessel displaying two red lights in a vertical line and a white light above them. What type of vessel is this likely to be?

  1. A vessel constrained by her draught
  2. A vessel not under command Correct answer.
  3. A vessel at anchor
  4. A vessel engaged in fishing

Explanation

Two red lights in a vertical line, with or without additional lights, indicate a vessel not under command. Such a vessel cannot manoeuvre as required by the Collision Regulations, so other vessels must keep well clear.

Question 30Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is using a chart whose horizontal datum differs from the GPS datum. What is the correct action before plotting GPS positions on the chart?

  1. Plot the GPS position directly and add a fixed 50-metre offset
  2. Use only visual bearings and discard the GPS
  3. Ignore the difference because GPS is always more accurate
  4. Apply the chart's stated datum shift to convert GPS positions before plotting Correct answer.

Explanation

If the chart datum differs from the GPS datum, positions must be converted using the datum shift stated on the chart before plotting. Plotting uncorrected GPS positions can place the vessel in error relative to charted hazards.

Question 31Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is approaching a harbour entrance and sees a charted light described as 'Fl R 4s 10m 8M'. What does the '8M' refer to?

  1. The length of the light's structure
  2. The distance from the harbour entrance
  3. The height of the light above sea level
  4. The nominal range of the light in nautical miles Correct answer.

Explanation

In a light characteristic such as 'Fl R 4s 10m 8M', the first figure after the colour and period is the height in metres and the final figure is the nominal range in nautical miles. The nominal range is the distance at which the light is visible in clear conditions.

Question 32Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is planning a passage that crosses a traffic separation scheme in Hong Kong waters. According to the Collision Regulations, how should the crossing be made?

  1. By following the traffic lane in the direction of flow only
  2. By crossing at the narrowest point regardless of angle
  3. At as close to right angles to the general direction of traffic flow as practicable Correct answer.
  4. By stopping and waiting for a gap in traffic

Explanation

Rule 10 requires a vessel crossing a traffic separation scheme to do so on a heading as close to right angles to the general direction of traffic flow as practicable. This minimises the time spent in the lane and reduces collision risk.

Question 33Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain sees a charted symbol of a black anchor with a red line through it in an area of Hong Kong waters. What does this indicate?

  1. A quarantine anchorage
  2. A prohibited anchoring area, such as over a submarine cable or pipeline Correct answer.
  3. A designated anchorage for small craft
  4. A place where anchoring is compulsory

Explanation

A black anchor crossed by a red line marks an area where anchoring is prohibited or should be avoided, commonly to protect submarine cables, pipelines or other installations. A coxswain should keep clear and anchor elsewhere.

Question 34Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is fixing position by a running fix while proceeding along a coast. What is the essential requirement for this method?

  1. Two simultaneous bearings on the same object
  2. A depth sounding taken at the same time as the bearing
  3. Three bearings taken within one minute
  4. A single bearing taken twice with the vessel's run between observations Correct answer.

Explanation

A running fix uses one position line observed at one time and a second position line observed later, with the vessel's course and distance run between them used to advance the first line. It is useful when only one object is available.

Question 35Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is navigating a narrow channel at night where several lights are visible. Which feature should be used to positively identify the channel limits?

  1. The brightest light in view
  2. The light with the highest elevation
  3. The nearest light regardless of its characteristic
  4. The charted light characteristics and their colours and rhythms Correct answer.

Explanation

At night, channel limits are identified by matching observed light characteristics, colours and rhythms to those charted. Brightness or proximity alone can be misleading because other lights may be brighter or closer.

Question 36Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain observes a charted light listed as 'Oc R 5s' but sees a steady red light with no occultations. What is the most likely explanation?

  1. The light is obscured by a background light
  2. The light has been changed to a fixed light and the chart is out of date Correct answer.
  3. The vessel is too close to see the occultations
  4. The occulting period is longer than five seconds

Explanation

If a light shows a steady character when the chart says occulting, the most likely cause is that the light has been altered and the chart or light list is out of date. A coxswain should check the latest notices to mariners and not rely on the old characteristic.

Question 37Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is planning a passage through Hong Kong waters and wants to know the latest changes to aids to navigation. Which source should be consulted?

  1. A general sailing guide published decades ago
  2. The chart's edition date only
  3. Notices to Mariners issued by the hydrographic authority Correct answer.
  4. The vessel's own logbook

Explanation

Notices to Mariners are the official means of announcing changes to charts, lights, buoys and other navigational information. A coxswain should check them regularly and correct the chart before passage planning.

Question 38Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is fixing position using a GPS receiver and a paper chart. Which practice best guards against a gross position error?

  1. Increasing the GPS update rate
  2. Relying solely on the GPS display without plotting
  3. Plotting the GPS position and cross-checking with a visual bearing or depth Correct answer.
  4. Turning off the chart plotter's alarm

Explanation

Plotting the GPS position and cross-checking it against an independent source such as a visual bearing, transit or depth sounding helps detect gross errors. A single electronic source should not be trusted without confirmation.

Question 39Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is planning a passage and notes that a charted drying height is shown as '2' with a subscript. What does a drying height indicate?

  1. The depth of water below chart datum at all times
  2. The height of the tide above mean sea level
  3. The height of the seabed above chart datum, exposed at low water Correct answer.
  4. The clearance under a bridge at high water

Explanation

A drying height shows how far the seabed lies above chart datum, so the feature dries and becomes exposed when the tide falls below that height. A coxswain must allow for the predicted tide when planning to pass over such an area.

Question 40Local knowledge and chartwork: Hong Kong waters, aids to navigation, passage planning and position fixing

A coxswain is proceeding up a channel and sees a green conical buoy on the starboard bow. In IALA Region A, what does this indicate?

  1. A safe water mark at the channel entrance
  2. The port-hand edge of the channel when proceeding in the direction of buoyage
  3. A hazard in mid-channel
  4. The starboard-hand edge of the channel when proceeding in the direction of buoyage Correct answer.

Explanation

In IALA Region A, green conical buoys mark the starboard-hand side of a channel when proceeding in the direction of buoyage. A coxswain should keep the buoy on the appropriate side to remain in the channel.

Question 41Collision regulations (International Regulations for Preventing Collisions at Sea) and safe navigation

Under the International Regulations for Preventing Collisions at Sea, which vessel is required to keep out of the way when a power-driven vessel meets a sailing vessel in open water?

  1. The sailing vessel, because sail has priority over all power-driven craft
  2. The power-driven vessel, because it is the give-way vessel in a crossing situation with a vessel under sail Correct answer.
  3. Whichever vessel is proceeding at the higher speed
  4. Neither vessel; both must alter course to starboard simultaneously

Explanation

Rule 18 establishes a hierarchy of responsibility, and a power-driven vessel underway must keep out of the way of a vessel under sail. The sailing vessel is the stand-on vessel and must hold her course and speed. Only in narrow channels or where local rules provide otherwise does the arrangement change.

Question 42Collision regulations (International Regulations for Preventing Collisions at Sea) and safe navigation

You are on a power-driven vessel and observe a steady white masthead light and a red sidelight ahead on your starboard bow, with no green sidelight visible. What does this indicate?

  1. A vessel crossing from your port side toward your starboard side
  2. A vessel overtaking you from astern
  3. A vessel approaching head-on
  4. A vessel crossing from your starboard side toward your port side Correct answer.

Explanation

Seeing only a red sidelight means you are looking at the port side of the other vessel, so she is crossing your bow from starboard to port. In this crossing situation you are the give-way vessel and must keep clear. If both sidelights and both masthead lights were visible, the vessels would be meeting nearly head-on.

Question 43Collision regulations (International Regulations for Preventing Collisions at Sea) and safe navigation

Two power-driven vessels are crossing so as to involve risk of collision, and the bearing between them is not changing. Which vessel must keep out of the way?

  1. The vessel proceeding downwind
  2. The vessel that has the other on her own port side
  3. The larger vessel
  4. The vessel that has the other on her own starboard side Correct answer.

Explanation

Rule 15 requires the vessel that has the other on her own starboard side to keep out of the way in a crossing situation. That vessel should normally avoid crossing ahead of the other and, if circumstances permit, alter course to starboard. The stand-on vessel maintains course and speed.

Question 44Collision regulations (International Regulations for Preventing Collisions at Sea) and safe navigation

A power-driven vessel is approaching another power-driven vessel from a direction more than 22.5 degrees abaft her beam. What is the status of the approaching vessel?

  1. She is the give-way vessel and must keep out of the way Correct answer.
  2. She is neither give-way nor stand-on until risk of collision is confirmed
  3. She is the stand-on vessel and must maintain course and speed
  4. She must sound one short blast and pass on the other vessel's port side

Explanation

Rule 13 defines an overtaking vessel as one coming from more than 22.5 degrees abaft the beam of the other, and any vessel overtaking another must keep out of the way. This obligation continues until she is finally past and clear. The overtaken vessel remains the stand-on vessel.

Question 45Collision regulations (International Regulations for Preventing Collisions at Sea) and safe navigation

In restricted visibility you hear one prolonged blast followed by two short blasts from a vessel whose position is not yet determined. What does this signal indicate?

  1. A vessel engaged in fishing
  2. A vessel not under command or restricted in her ability to manoeuvre, making way Correct answer.
  3. A power-driven vessel making way through the water
  4. A vessel underway but stopped, making no way through the water

Explanation

Under Rule 35, one prolonged blast followed by two short blasts is the fog signal of a vessel not under command, a vessel restricted in her ability to manoeuvre, a vessel constrained by her draught, a sailing vessel, or a vessel engaged in fishing, when making way. The same vessels at anchor or stopped sound two prolonged blasts with an interval between them.

Question 46Collision regulations (International Regulations for Preventing Collisions at Sea) and safe navigation

What is the required arc of visibility for a vessel's sidelights?

  1. From dead ahead to 22.5 degrees on each side
  2. From dead ahead to 135 degrees on each side
  3. From dead ahead to 112.5 degrees on each side Correct answer.
  4. The full 360 degrees around the vessel

Explanation

Sidelights show from right ahead to 22.5 degrees abaft the beam on their respective sides, giving an arc of 112.5 degrees each. The red light is on the port side and the green on the starboard side. The masthead light, by contrast, covers an arc of 225 degrees.

Question 47Collision regulations (International Regulations for Preventing Collisions at Sea) and safe navigation

A power-driven vessel of 12 metres in length is underway at night and is able to show the lights required for her size. Which combination is acceptable?

  1. A masthead light, a sternlight, and sidelights, or an all-round white light and sidelights Correct answer.
  2. A sternlight and sidelights only
  3. Sidelights only
  4. An all-round white light only

Explanation

Rule 23 allows a power-driven vessel of less than 12 metres to carry either the standard masthead light, sternlight and sidelights, or an all-round white light and sidelights. At 12 metres she must comply with the standard configuration. Sidelights are always required when underway.

Question 48Collision regulations (International Regulations for Preventing Collisions at Sea) and safe navigation

What does a vessel display when at anchor in daylight?

  1. One black cone pointing downward
  2. One black ball forward Correct answer.
  3. Two black balls in a vertical line
  4. Three black balls in a vertical line

Explanation

Rule 30 requires a vessel at anchor to exhibit one black ball forward where it can best be seen. At night she shows an all-round white light, plus a second all-round white light aft if she is 50 metres or more in length. A cone pointing down indicates a vessel under sail also using power.

Question 49Collision regulations (International Regulations for Preventing Collisions at Sea) and safe navigation

You are the give-way vessel in a crossing situation and there is risk of collision. What is the first action the rules require?

  1. Sound one short blast and maintain your course
  2. Take early and substantial action to keep well clear Correct answer.
  3. Wait for the stand-on vessel to alter course first
  4. Reduce speed to bare steerageway and hold your heading

Explanation

Rule 16 requires the give-way vessel to take early and substantial action to keep well clear. A series of small alterations should be avoided, and any alteration should be large enough to be readily apparent to the other vessel. Waiting for the stand-on vessel to act defeats the purpose of the rule.

Question 50Collision regulations (International Regulations for Preventing Collisions at Sea) and safe navigation

Which statement correctly describes the action required of a stand-on vessel when the give-way vessel is not taking appropriate action?

  1. She must always maintain course and speed regardless of the circumstances
  2. She must immediately alter course to port
  3. She may take action by her own manoeuvre as soon as it becomes apparent the give-way vessel is not complying Correct answer.
  4. She must stop her engines and sound five short blasts

Explanation

Rule 17 permits the stand-on vessel to take action as soon as it becomes apparent the give-way vessel is not taking appropriate action. Where possible she should avoid altering course to port for a vessel on her own port side. If collision cannot be avoided by the give-way vessel alone, she must take the best action to avoid it.