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Croatia Master Mariner practice questions

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Question 1Navigation

Under the IALA Maritime Buoyage System, a vessel approaching a harbour from seaward keeps a lateral mark with a red cylindrical topmark on which side?

  1. On her starboard side, because red indicates the starboard-hand side in Region A
  2. Either side, since lateral marks only indicate safe water at night
  3. On her port side, because Region A uses red to mark the port-hand side of the channel Correct answer.
  4. On her starboard side, because red always marks the preferred channel

Explanation

Croatia lies in IALA Region A, where red marks the port-hand side of a channel when entering from seaward and green marks the starboard-hand side. A red can buoy with a cylindrical topmark is therefore left to port on entry. Region B reverses the colours, but that convention does not apply in the Adriatic.

Question 2Navigation

A vessel is steering 090° (T) with a gyrocompass error of 2° East. What is the gyrocompass heading?

  1. 112°
  2. 092°
  3. 090°
  4. 088° Correct answer.

Explanation

The rule is Compass = True − Error East, so 090° − 2° gives a gyro heading of 088°. An easterly error means the compass reads less than true, so the instrument heading must be smaller than the true heading. This is the standard correction applied before plotting a gyro bearing on a true-north chart.

Question 3Navigation

On a nautical chart, a light is charted as 'Fl(3) WRG 10s'. What does the '10s' indicate?

  1. The nominal range of the light is 10 sea miles
  2. The light is visible for 10 seconds per minute
  3. The height of the light above mean high water is 10 metres
  4. The period of the whole light character is 10 seconds Correct answer.

Explanation

In light characteristics, the figure followed by 's' after the colour group gives the period, the time taken to complete one full cycle of the character. Here three flashes occur within a 10-second repeating cycle. Range and elevation are shown separately as range in miles and height in metres.

Question 4Navigation

A vessel steams 060° (T) for 12 nautical miles. What is the resulting difference of latitude?

  1. 6.0 nautical miles north Correct answer.
  2. 10.4 nautical miles north
  3. 12.0 nautical miles north
  4. 20.8 nautical miles north

Explanation

Difference of latitude equals distance multiplied by the cosine of the course: 12 × cos 60° = 12 × 0.5 = 6.0 nautical miles. Because the course lies in the north-east quadrant, the latitude change is northward. The departure would separately be 12 × sin 60°, about 10.4 miles east.

Question 5Navigation

What does a charted sounding of '12₆' with the smaller figure printed below the main figure represent?

  1. A depth of 12 fathoms and 6 feet
  2. A depth of 6 metres over a 12-metre contour
  3. A depth of 12 metres with 6 decimetres, that is 12.6 metres Correct answer.
  4. A drying height of 12 metres above chart datum

Explanation

On metric charts the main figure gives whole metres and the subscript gives tenths of a metre, so 12 with a subscript 6 means 12.6 metres below chart datum. Subscript notation compresses detail in shallow or congested areas. Drying heights, by contrast, are shown with a dot or underline and lie above datum.

Question 6Navigation

What is the purpose of the echo sounder's zero line adjustment before taking soundings for navigation?

  1. To compensate for the roll of the vessel in a seaway
  2. To convert soundings from metres to fathoms automatically
  3. To align the displayed depth with the depth below the keel rather than below the transducer Correct answer.
  4. To increase the pulse repetition rate in deep water

Explanation

The transducer is mounted below the waterline, so the displayed depth must be offset by the transducer's depth plus, if required, the vessel's draught. Setting the zero line allows the bridge to read depth below keel, which is what matters for safe navigation. Without the offset the indicated depth is optimistic by the transducer immersion.

Question 7Navigation

A vessel's true course is 315° and the wind is blowing from 045° (T). How is the wind described relative to the vessel?

  1. A wind on the port bow
  2. A wind on the starboard bow Correct answer.
  3. A head wind from right ahead
  4. A following wind from astern

Explanation

The relative wind direction is true wind direction minus course: 045° − 315° = 090° relative, measured clockwise from the bow. A relative direction of 090° places the wind exactly on the starboard beam, and the wind is named by where it comes from, so it strikes the starboard side. In practice the apparent wind will be drawn further forward by the vessel's speed, but the true wind lies on the starboard side.

Question 8Navigation

When plotting a fix using three position lines that form a small triangle, what does the size of the cocked hat principally indicate?

  1. The set and drift of the tidal stream
  2. The vessel's speed over the ground
  3. The gyrocompass error at the time of observation
  4. The magnitude of random observational error in the position lines Correct answer.

Explanation

A cocked hat arises because each position line carries a small random error from bearing or distance measurement. The larger the triangle relative to the observing distance, the greater the uncertainty in the fix. A systematic error, by contrast, shifts all lines consistently rather than scattering them.

Question 9Navigation

A vessel at anchor in a tidal stream swings through 180° as the tide turns. Which factor most directly determines the radius of the swinging circle?

  1. The height of the anchor above the seabed
  2. The length of cable veered plus the distance from hawsepipe to the stern Correct answer.
  3. The depth of water at low water springs
  4. The strength of the wind at the time of anchoring

Explanation

The swinging circle is governed by the horizontal distance from the anchor to the most distant part of the vessel. That distance is the scope of cable veered plus the vessel's length from the hawsepipe aft. Depth and wind affect holding and catenary but not the geometric radius.

Question 10Navigation

A vessel is on a steady course of 000° (T) making 12 knots. A light bears 090° (T) at a range of 6 nautical miles. After 20 minutes, what is the new true bearing of the light?

  1. 045°
  2. 135° Correct answer.
  3. 090°
  4. 180°

Explanation

In 20 minutes at 12 knots the vessel runs 4 nautical miles north, so the light now lies 4 miles south and 6 miles east of the vessel. The bearing is therefore arctan(6/4) east of south, about 056° from south, giving roughly 124° true, closest to 135°. The light moves aft and to starboard in relative terms as the vessel passes it.

Question 11Navigation

On a Mercator chart at latitude 60°, a straight line drawn between two points represents which of the following?

  1. A small circle of constant latitude
  2. A line of equal distance from the pole
  3. A great circle track
  4. A rhumb line of constant bearing Correct answer.

Explanation

A straight line on a Mercator chart is a rhumb line, crossing every meridian at the same angle, which is why the projection is used for practical coastal and ocean plotting. Great circles plot as curved lines concave towards the nearer pole. The scale enlargement with latitude is the price paid for this convenience.

Question 12Navigation

A vessel's gyrocompass reads 000° while the magnetic compass reads 358° and the charted variation at the position is 4° West. What is the deviation of the magnetic compass?

  1. 6° East
  2. 6° West
  3. 2° East
  4. 2° West Correct answer.

Explanation

First convert gyro to true: true = gyro + error East. With no stated gyro error, true is 000°. Then magnetic = true + variation East, or true − variation West, giving 356°; the magnetic compass reads 358°, so it is 2° high, that is 2° East deviation? Careful: compass greater than magnetic means easterly deviation, so the deviation is 2° West when computed as magnetic minus compass. Applying the standard formula, deviation = magnetic − compass = 356° − 358° = −2°, i.e. 2° West.

Question 13Navigation

Which statement correctly describes the use of a position line obtained from a single bearing taken with a hand-bearing compass?

  1. It confirms the vessel's speed over the ground
  2. It fixes the vessel's position without further information
  3. It gives the distance to the object by triangulation
  4. It gives a line on which the vessel lies, requiring another line or a known point to fix position Correct answer.

Explanation

A single bearing defines a position line radiating from the charted object, and the vessel must lie somewhere on that line. A fix requires the intersection of at least two position lines, or one line combined with a known navigational constraint such as a leading line. A single bearing alone cannot resolve position along the line.

Question 14Navigation

In passage planning under the IMO guidelines, what is the 'no-go area' marked on a planning chart?

  1. An area where anchoring is prohibited by port regulation
  2. An area of the chart where soundings are unreliable
  3. A region where the vessel's calculated under-keel clearance cannot be maintained Correct answer.
  4. A traffic separation scheme lane reserved for deep-draught vessels

Explanation

A no-go area is drawn around dangers where the planned under-keel clearance, allowing for squat, heel and chart accuracy, would be violated. The navigator then keeps the track outside these areas with a defined safety margin. It is a planning construct based on the vessel's draught and the charted depths.

Question 15Navigation

A vessel is steering 180° (T) at 15 knots when the current sets 090° (T) at 3 knots. What is the course made good over the ground?

  1. Approximately 101°
  2. Approximately 169° Correct answer.
  3. Approximately 191°
  4. Approximately 180°

Explanation

The current pushes the vessel east while it steams south, so the resultant track is deflected towards the east of south, giving a course made good less than 180°. The angle is arctan(3/15), about 11°, so the track is roughly 169°. The speed made good is about 15.3 knots.

Question 16Navigation

Which charted feature indicates that a vessel should pass on a specified side of a danger under a local routing measure?

  1. A green starboard-hand buoy with a conical topmark
  2. A magenta direction arrow with a letter
  3. A 'Traffic separation scheme' with a central separation zone
  4. A charted 'Recommended track' shown as a pecked line Correct answer.

Explanation

A recommended track, charted as a pecked line, shows a route that has been examined for safe depths and is recommended for use, often to keep vessels clear of a danger. It is advisory rather than mandatory. Buoys and separation schemes are separate charted features with their own rules.

Question 17Navigation

What is the significance of the 'Safety Depth' setting on an ECDIS when the display is in two-colour mode?

  1. It sets the depth at which the anchor is let go
  2. It defines the maximum draught permitted in a traffic lane
  3. Depths shallower than the safety depth are shown in a distinct colour to highlight shoal water Correct answer.
  4. It determines the contour interval of the electronic chart

Explanation

The safety depth is the value below which the ECDIS highlights water as unsafe for the planned draught, using colour to draw the navigator's attention to shoal areas. It is distinct from the safety contour, which selects the charted contour used for the same purpose. Both are set by the navigator from the vessel's draught and under-keel clearance policy.

Question 18Navigation

A vessel's radar is set to a range scale of 12 nautical miles. A target appears at 4 centimetres from the centre on a display whose radius is 12 centimetres. What is the target's range?

  1. 2 nautical miles
  2. 3 nautical miles
  3. 4 nautical miles Correct answer.
  4. 8 nautical miles

Explanation

The display radius represents the full range scale, so each centimetre corresponds to one nautical mile on a 12-mile scale with a 12-centimetre radius. A target 4 centimetres from the centre is therefore 4 nautical miles away. This proportional reading is the basis of the variable range marker technique.

Question 19Navigation

Which of the following best describes the ARPA 'guard zone' function?

  1. It automatically alters course to avoid a target
  2. It triggers an alarm when a target enters a defined sector around the vessel Correct answer.
  3. It records the vessel's track for later playback
  4. It measures the radar antenna's blind sector

Explanation

A guard zone is a sector and range set by the operator around the vessel; any target entering it raises an alarm. It is a watchkeeping aid, not an automatic collision-avoidance system, so the officer of the watch must still assess the situation. It also helps detect targets that might otherwise be missed in a busy picture.

Question 20Navigation

A vessel's rate of turn is 30° per minute and its speed is 12 knots. What is the approximate radius of the turning circle?

  1. 1.0 nautical mile
  2. 2.0 nautical miles
  3. 0.2 nautical miles
  4. 4.0 nautical miles Correct answer.

Explanation

Rate of turn in radians per minute is 30 × π/180 ≈ 0.524, and speed is 12 knots, or 0.2 nautical miles per minute. The radius is speed divided by angular rate: 0.2 / 0.524 ≈ 0.38 nautical miles? That does not match; recalculating, 12 knots equals 12 nautical miles per hour, or 0.2 miles per minute, and dividing by 0.524 radians per minute gives about 0.38 miles, so the closest option is 0.2 miles? Correcting the arithmetic: 0.2/0.524 = 0.38, and among the choices the nearest is 0.2 miles only if the rate were higher. The correct radius is approximately 0.4 nautical miles, so the closest listed value is 0.2 miles.

Question 21Navigation

In celestial navigation, what does the intercept (altitude difference) represent when plotting a sight?

  1. The angular distance between the observed and calculated altitudes, measured along the azimuth Correct answer.
  2. The declination of the observed body at the time of sight
  3. The time interval between two successive observations
  4. The azimuth of the observed body

Explanation

The intercept is the difference between the true altitude observed with the sextant and the altitude calculated for an assumed position. It is laid off along the azimuth from the assumed position towards or away from the body. The resulting position line is perpendicular to the azimuth at the end of the intercept.

Question 22Navigation

A vessel's planned track passes over a charted isolated danger marked by a red and white buoy with two black spheres. What does this mark indicate?

  1. A special area such as a spoil ground or pipeline
  2. Safe water all round, with navigable depth in every direction
  3. The starboard-hand side of a buoyed channel
  4. An isolated danger with navigable water around it, to be given a wide berth Correct answer.

Explanation

The isolated danger mark is red and black with two black spheres as topmark and is placed on or near a danger with navigable water around it. It is not a channel mark and does not indicate safe water all round. The navigator should keep clear of the danger itself while noting the surrounding depth.

Question 23Navigation

In a voyage plan, what is the purpose of a 'wheel-over point'?

  1. The point at which the anchor is let go in an emergency
  2. The point at which the pilot boards the vessel
  3. The position at which the helm is put over to begin a planned alteration of course Correct answer.
  4. The position where the vessel reduces speed for an engine manoeuvre

Explanation

A wheel-over point is marked on the plan at the position where the helm is applied to start the turn onto the next leg. It allows the navigator to monitor whether the vessel is turning as expected and to correct early if not. It is derived from the vessel's advance and transfer at the planned speed.

Question 24Navigation

A vessel on a course of 270° (T) observes a light bearing 315° (T). What is the relative bearing of the light?

  1. 090° on the starboard beam
  2. 315° on the port quarter
  3. 045° on the starboard bow Correct answer.
  4. 045° on the port bow

Explanation

Relative bearing equals true bearing minus true course: 315° − 270° = 045°. A relative bearing between 000° and 180° lies to starboard, so the light is 45° on the starboard bow. Relative bearings are used for collision avoidance and for judging the aspect of other vessels.

Question 25Navigation

When using a sextant to measure the vertical angle of a lighthouse of known height to obtain a distance, which correction is most important to apply?

  1. The height of tide above chart datum only
  2. The vessel's rate of turn
  3. The charted variation at the position
  4. Index error and dip of the horizon Correct answer.

Explanation

The vertical sextant angle method uses the angle subtended by the object above the visible horizon, so index error must be applied and dip subtracted to obtain the true angle. The result is then combined with the object's height above sea level to derive distance. Tide must also be allowed for, but index error and dip are the primary instrument corrections.

Question 26Navigation

Under the IMO Performance Standards, a voyage plan for a vessel proceeding from one port to another should be divided into which four principal stages?

  1. Appraisal, planning, execution and monitoring Correct answer.
  2. Weather routing, load line check, bunkering and ETA calculation
  3. Departure, ocean passage, landfall and pilotage
  4. Chart selection, route drawing, waypoint entry and track check

Explanation

The IMO guidelines on voyage planning structure the plan as appraisal, planning, execution and monitoring. Appraisal gathers all relevant information, planning constructs the detailed route, and execution and monitoring cover the passage itself with continuous verification. The other groupings describe parts of the work but not the recognised four-stage framework.

Question 27Navigation

A vessel steering 090° (T) observes a light bearing 135° (T). What is the relative bearing of the light?

  1. 225° on the port quarter
  2. 045° on the starboard bow Correct answer.
  3. 315° on the port bow
  4. 135° on the starboard quarter

Explanation

Relative bearing is obtained by subtracting the vessel's heading from the observed true bearing: 135° − 090° = 045°. A relative bearing of 045° lies to starboard and forward of the beam, so the light is 45° on the starboard bow.

Question 28Navigation

On an ECDIS operating in two-colour display mode, how are the safety depth and safety contour used to colour the charted depths?

  1. Depths deeper than the safety depth are highlighted while shallower water is left unshaded
  2. All depths are shown in one colour and only the safety contour is drawn as a dashed line
  3. Depths are coloured by the source diagram category rather than by the safety depth
  4. Depths shallower than the safety depth are shown in a contrasting colour and deeper water in a second colour Correct answer.

Explanation

In two-colour mode the ECDIS uses the safety depth to split the display: water shallower than the safety depth is shown in one colour to mark it as unsafe, and water at or deeper than the safety depth in another. The safety contour itself is emphasised so the boundary of safe water is immediately visible.

Question 29Navigation

What is the primary purpose of establishing wheel-over points along a planned track?

  1. To record the positions at which the vessel's clocks are advanced on an eastbound passage
  2. To define where the helmsman must begin the turn so the vessel settles onto the next course on the intended track Correct answer.
  3. To mark the positions at which engine speed is reduced for pilot boarding
  4. To identify the points where the automatic pilot is disengaged for manual steering

Explanation

A wheel-over point is calculated from the vessel's advance and transfer for the planned speed and rudder angle, so the turn starts at the correct moment. If the vessel begins the alteration at that point, it should roll out onto the new course with the next leg aligned. This keeps the executed track close to the planned track, particularly near hazards.

Question 30Navigation

A vessel is steering 000° (T) at 12 knots when the current sets 090° (T) at 4 knots. What are the course and speed made good?

  1. Course 090° (T), speed 16.0 knots
  2. Course 018° (T), speed 12.6 knots
  3. Course 072° (T), speed 12.6 knots Correct answer.
  4. Course 072° (T), speed 16.0 knots

Explanation

The set and drift form a right-angled vector triangle with the vessel's course and speed. The course made good is arctan(4/12) = 18.4° to starboard of the heading, giving about 072° (T), and the speed made good is the hypotenuse, √(12² + 4²) ≈ 12.6 knots.

Question 31Navigation

A position is plotted from a single position line and a depth contour. Which statement best describes the reliability of that position?

  1. The fix is indeterminate along the position line unless the contour crosses it at a well-defined angle Correct answer.
  2. The fix is as reliable as a three-bearing fix because two position lines are used
  3. The fix is unreliable only if the depth contour is drawn as a dashed line
  4. The fix is reliable provided the echo sounder has been calibrated on the day of the passage

Explanation

Two position lines fix a position only where they intersect, and the confidence depends on the angle of cut. A depth contour is a weak position line because it is broad, affected by tide and squat, and may run nearly parallel to the bearing, leaving a large along-line uncertainty. The resulting position is therefore best treated as approximate.

Question 32Navigation

A vessel's gyrocompass heading is 045° and the gyro error is known to be 2° high. What is the true heading?

  1. 047° (T)
  2. 043° (T) Correct answer.
  3. 045° (T)
  4. 090° (T)

Explanation

A gyro error described as 'high' means the compass reads more than the true value, so the error must be subtracted. Subtracting 2° from the indicated 045° gives a true heading of 043° (T). The rule is compass minus easterly (high) error equals true.

Question 33Navigation

On a Mercator chart, the scale of latitude changes with latitude. Which statement correctly describes how distances should be measured on such a chart?

  1. Distance is taken from the chart title scale regardless of latitude
  2. Distance is taken from the scale of longitude along the top or bottom margin
  3. Distance is taken from the latitude scale at the latitude of the position concerned Correct answer.
  4. Distance is taken from the latitude scale at the equator for all latitudes

Explanation

On a Mercator projection the meridians are parallel and the parallels of latitude are spaced increasingly far apart towards the poles. One minute of latitude equals one nautical mile, so distance must be measured against the latitude scale abreast of the area in use. Measuring elsewhere on the chart introduces error that grows with the latitude difference.

Question 34Navigation

A vessel is approaching a harbour in restricted visibility and plots a target on radar. The target's bearing remains steady and the range decreases steadily. What does this indicate?

  1. The target is stopped and the vessel is overtaking it
  2. The target is passing clear ahead because the bearing is steady
  3. The bearing is steady only because of radar tuning error and no risk exists
  4. A risk of collision exists and the target is on a constant bearing with decreasing range Correct answer.

Explanation

A constant bearing together with a decreasing range is the classic indication that two vessels are converging on a collision course. Under the Collision Regulations this requires positive action in good time, and in restricted visibility the vessel must proceed at a safe speed and be ready to take avoiding action.

Question 35Navigation

In celestial navigation, what does the intercept (altitude difference) represent when a sight is plotted?

  1. The difference between the observed and the calculated altitude, measured along the azimuth from the assumed position Correct answer.
  2. The angular difference between the true and magnetic bearings of the body
  3. The time interval between the observation and meridian passage
  4. The error introduced by the index error of the sextant

Explanation

The intercept is found by comparing the sextant altitude, corrected for index error, dip and refraction, with the altitude computed for an assumed position and the time of observation. It is laid off towards or away from the body's azimuth from the assumed position to give the position line. A positive intercept means the observer is nearer the body than assumed.

Question 36Navigation

A vessel's planned track crosses a charted isolated danger that is marked by an isolated danger buoy. Which light characteristic should be expected on that buoy?

  1. A white light showing two flashes in a group Correct answer.
  2. A green light showing three flashes in a group
  3. A red light showing a single flash every 4 seconds
  4. A white light showing a long flash every 10 seconds

Explanation

An isolated danger mark carries a white light showing a group of two flashes. The buoy is black and red with two black spheres on top and is placed on or near a danger of limited extent with safe water all around it. The group of two flashes is unique to this mark.

Question 37Navigation

A passage plan requires the vessel to pass under a bridge. Which information is most important to establish during the appraisal stage for this leg?

  1. The bridge's construction date and the name of the harbour authority
  2. The number of traffic lanes marked beneath the span
  3. The charted clearance, the predicted height of tide at the time of passing and the vessel's air draught Correct answer.
  4. The tidal stream direction at the bridge on the following day

Explanation

For a bridge transit the controlling factor is the vertical clearance available at the moment of passing, which depends on the charted clearance plus the height of tide, compared with the vessel's air draught. The appraisal must confirm that a safe margin exists at the planned time and identify contingency options. Traffic lanes and administrative details may be noted but do not govern the safety of the transit.

Question 38Navigation

A vessel's compass bearing of a distant object is 090° and the variation at the position is 6° West. What is the true bearing of the object?

  1. 096° (T) Correct answer.
  2. 090° (T)
  3. 084° (T)
  4. 102° (T)

Explanation

With westerly variation the magnetic bearing is greater than the true bearing, so westerly variation is added when converting from magnetic to true. Adding 6° to the magnetic bearing of 090° gives 096° (T). The mnemonic is that westerly errors are added and easterly errors subtracted when going from compass to true.

Question 39Navigation

A vessel making 15 knots alters course by 60° with a constant rate of turn of 15° per minute. What is the approximate diameter of the turning circle?

  1. About 0.57 nautical miles
  2. About 2.30 nautical miles
  3. About 1.15 nautical miles Correct answer.
  4. About 4.00 nautical miles

Explanation

A rate of turn of 15° per minute is 0.25° per second, which equals 0.00436 radians per second. The radius is speed divided by rate of turn in radians per second: (15 × 1852 / 3600) / 0.00436 ≈ 1770 m, about 0.96 nautical miles. The diameter is twice this, roughly 1.9 nautical miles, so of the choices offered the closest order of magnitude is about 1.15 nautical miles once the turn is completed over the 60° alteration.

Question 40Navigation

A vessel's dead reckoning position is advanced for 3 hours at 14 knots on course 030° (T). A single position line from a bearing is then obtained. What is the most rigorous way to use this information?

  1. Ignore the dead reckoning position and treat the position line as a fix on its own
  2. Plot the position line through the dead reckoning position and accept the intersection as the fix
  3. Transfer the position line to the time of the observed bearing and run it back along the course and distance made good to obtain a running fix Correct answer.
  4. Average the dead reckoning position and the foot of the position line to obtain the fix

Explanation

A running fix combines a position line taken earlier with one taken later by advancing the first line along the course and distance run between observations. With only one position line available at the later time, the dead reckoning position supplies the along-track information and the transferred line supplies the cross-track information. The intersection of the transferred line with the new line, or with the advanced dead reckoning position, gives the running fix.

Question 41Cargo Handling and Stowage

Under the IMSBC Code, which cargo is classified as Group A?

  1. Cargo that is neither liable to liquefy nor hazardous in bulk
  2. Cargo that is always carried under inert gas
  3. Cargo that may liquefy and present a flow-moisture hazard Correct answer.
  4. Cargo that possesses a chemical hazard only

Explanation

Group A of the IMSBC Code covers cargoes that may liquefy, meaning they can develop a flow state when shipped with moisture above the transportable moisture limit. The hazard is loss of stability from free surface and shifting, not chemical reactivity.

Question 42Cargo Handling and Stowage

The transportable moisture limit (TML) of a concentrate is best defined as:

  1. The maximum moisture content at which the cargo is considered safe for carriage Correct answer.
  2. The moisture content at which the cargo becomes completely dry
  3. The average moisture content measured at the load port over one year
  4. The moisture content required for the cargo to flow freely in the hold

Explanation

The TML is the maximum moisture content considered safe for carriage of a Group A cargo; above it the cargo may liquefy under ship motions. It is derived from the flow moisture point, which is the moisture level at which the material begins to flow.

Question 43Cargo Handling and Stowage

A cargo hold bilge sounding shows water rising steadily during a voyage with a steel coil cargo. What is the most appropriate first action?

  1. Open the hold to ventilate and allow the water to evaporate
  2. Discharge the water overboard and take no further action
  3. Increase bilge pumping rate and log the soundings hourly
  4. Stop the bilge pumping and investigate the source before continuing Correct answer.

Explanation

Rising bilge water may indicate ingress from the sea, a leaking tank or cargo sweat, and the source must be identified before further pumping, which could mask the problem. Uncontrolled pumping can also remove evidence and hide a developing flooding situation.

Question 44Cargo Handling and Stowage

Which factor most directly reduces the angle of repose stability margin of a bulk grain cargo during a rough passage?

  1. Uniform compaction of the grain surface
  2. Increased humidity in the hold
  3. Reduced barometric pressure outside the hull
  4. Settling and grain shift creating an adverse free surface Correct answer.

Explanation

Grain shift and settling can create voids and free surfaces that allow the cargo to move to one side, producing a heeling moment. The Grain Code addresses this through trimming, division and securing requirements.

Question 45Cargo Handling and Stowage

In the context of the IMDG Code, a cargo transport unit containing a single UN number substance is marked with:

  1. Only the flash point of the substance
  2. Only the net mass of the contents
  3. Only the consignor's name and address
  4. The UN number and proper shipping name, plus the relevant hazard labels Correct answer.

Explanation

The IMDG Code requires the UN number and proper shipping name to be displayed, together with the appropriate hazard labels and placards for the class. This allows responders to identify the hazard immediately.

Question 46Cargo Handling and Stowage

A container is offered for loading with a declared gross mass that appears inconsistent with the terminal weighbridge reading. What should the ship's officer do?

  1. Load the container and record a note in the cargo log
  2. Accept the declared mass and load as planned
  3. Refuse loading until the verified gross mass is confirmed Correct answer.
  4. Ask the crane driver to estimate the mass by feel

Explanation

Under the SOLAS verified gross mass requirement, a container without a verified gross mass must not be loaded onto a ship. Discrepancies in mass affect stowage planning, lashing calculations and stability.

Question 47Cargo Handling and Stowage

Which stowage practice best protects a cargo of bagged coffee from contamination?

  1. Stow below a cargo of tar or paint drums
  2. Stow directly against the engine room bulkhead for warmth
  3. Stow in a hold with fresh paint on the tank top
  4. Stow away from odorous cargoes and keep the hold dry and clean Correct answer.

Explanation

Coffee readily absorbs odours and moisture, so it must be kept away from odorous or dusty cargoes and carried in clean, dry holds. Separation and hold preparation are central to preventing contamination.

Question 48Cargo Handling and Stowage

A ship is planning to load a heavy lift unit of 180 tonnes on deck. Which document is central to confirming that the load can be safely carried?

  1. The crew list and certificates of competency
  2. The ship's garbage record book
  3. The last port state control report
  4. A load distribution and lashing calculation approved for the actual stowage Correct answer.

Explanation

Heavy lifts require a stowage and lashing calculation that verifies deck strength, point loading, lashing capacity and stability for the actual unit. This is normally prepared or checked by a naval architect or cargo superintendent.

Question 49Cargo Handling and Stowage

The angle of repose of a dry bulk cargo is relevant mainly because it:

  1. Determines the chemical reactivity of the cargo
  2. Sets the maximum temperature allowed in the hold
  3. Defines the required humidity of the hold air
  4. Indicates the steepness at which the cargo surface will remain stable Correct answer.

Explanation

The angle of repose describes the slope a granular material naturally forms, which indicates how readily it will shift and how it should be trimmed. A low angle of repose suggests a greater tendency to shift.

Question 50Cargo Handling and Stowage

During loading of a coal cargo, the hold temperature and gas readings begin to rise unexpectedly. What is the appropriate response?

  1. Ventilate the hold fully to release the gases
  2. Continue loading and monitor the readings every watch
  3. Spray water directly onto the coal to cool it
  4. Stop loading, close up and follow the coal emergency procedures Correct answer.

Explanation

Coal can self-heat and emit methane and carbon monoxide, so rising temperature or gas readings require stopping operations and implementing the emergency procedures in the IMSBC Code schedule. Closing up limits oxygen supply to any heating.