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Iran Deck Officer (STCW II/2) Certificate of Competency Examination study materials
Iran Deck Officer (STCW II/2) Certificate of Competency Examination study resources

Iran Deck Officer (STCW II/2) Certificate of Competency Examination practice questions

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Question 1Navigation

Under COLREG Rule 13, a vessel is deemed to be overtaking another when it approaches from a direction more than how many degrees abaft the other vessel's beam?

  1. 90 degrees
  2. 45 degrees
  3. 22.5 degrees Correct answer.
  4. 112.5 degrees

Explanation

Rule 13 defines an overtaking vessel as one coming up from a direction more than 22.5 degrees abaft the beam of the other vessel, i.e. from outside the forward sector where she would be able to see the other vessel's sidelights. At night this corresponds to seeing only the sternlight and neither sidelight.

Question 2Navigation

A power-driven vessel underway at night shows, in addition to sidelights and a sternlight, two masthead lights in a vertical line. Which description fits this vessel?

  1. A vessel 50 metres or more in length Correct answer.
  2. A vessel less than 50 metres in length
  3. A vessel engaged in towing, whatever her length
  4. A vessel constrained by her draught

Explanation

Rule 23 requires a power-driven vessel of 50 metres or more in length to exhibit a second masthead light abaft of and higher than the forward one. Vessels under 50 metres may show the second light but are not required to. Towing and constrained-by-draught status are shown by additional or different lights, not merely by the second masthead light.

Question 3Navigation

In IALA Region A, which buoy marks the port side of a channel when proceeding in the conventional direction of buoyage?

  1. A yellow spherical buoy
  2. A black-and-red horizontally banded buoy
  3. A red can buoy Correct answer.
  4. A green conical buoy

Explanation

Region A lateral marks use red to port and green to starboard when entering from seaward. The port-hand mark is red and normally can-shaped, while the starboard-hand mark is green and conical. Yellow and horizontally banded black-red buoys belong to other mark categories.

Question 4Navigation

The gyrocompass error is recorded as 3 degrees East. What is the true bearing if the compass bearing of a light is 045 degrees?

  1. 048 degrees Correct answer.
  2. 318 degrees
  3. 042 degrees
  4. 045 degrees

Explanation

The memory aid is Compass least, Error east, so with an easterly error the true bearing is greater than the compass bearing. Adding 3 degrees East to 045 degrees gives a true bearing of 048 degrees. Subtracting the error would apply the rule for a westerly error.

Question 5Navigation

A vessel's speed made good is 12 knots and the distance to the next waypoint is 42 nautical miles. What is the expected passage time?

  1. 3 hours 30 minutes Correct answer.
  2. 2 hours 50 minutes
  3. 3 hours 50 minutes
  4. 4 hours 12 minutes

Explanation

Time equals distance divided by speed, so 42 nautical miles divided by 12 knots gives 3.5 hours, which is 3 hours 30 minutes. The units are consistent because speed in knots is nautical miles per hour.

Question 6Navigation

On a Mercator chart, what happens to the spacing between parallels of latitude as latitude increases?

  1. It decreases towards the poles
  2. It increases only between 0 and 30 degrees north
  3. It remains constant everywhere
  4. It increases towards the poles Correct answer.

Explanation

The Mercator projection expands the latitude scale progressively towards the poles so that the rhumb line plots as a straight line. This is why one minute of latitude must always be measured from the latitude scale abreast of the position. The longitude scale remains constant.

Question 7Navigation

Which statement correctly defines variation?

  1. The angular difference between the ship's heading and the direction of travel through the water
  2. The angle between the magnetic meridian and the compass needle caused by the ship's magnetism
  3. The angular difference between true north and magnetic north at a given place Correct answer.
  4. The error introduced into a bearing by the ship's heel and pitch

Explanation

Variation is the angle between the true and magnetic meridians at the observer's position, caused by the Earth's magnetic field and shown on the chart as isogonals. Deviation, by contrast, is caused by the vessel's own magnetic field. Leeway concerns the difference between heading and track through the water.

Question 8Navigation

What is the meaning of a charted depth of 5 with subscript 2, written as 5 with a small 2 beside it?

  1. 5 metres depth with a 2 metre shoal patch nearby
  2. 5 metres depth with 2 metres of overfall
  3. 5 metres depth with 2 metres of tidal range
  4. 5 metres drying height with 2 metres above chart datum Correct answer.

Explanation

A depth figure with a subscript denotes a drying height, meaning the feature dries 5 metres at chart datum and has 2 metres of water over it at the stated state of tide. Drying heights are measured upward from chart datum. Normal soundings are printed as plain figures.

Question 9Navigation

A vessel steering 000 degrees true at 15 knots experiences a current setting 090 degrees true at 3 knots. What is the course and speed made good?

  1. 348.7 degrees at 15.3 knots
  2. 090 degrees at 3.0 knots
  3. 000 degrees at 18.0 knots
  4. 011.3 degrees at 15.3 knots Correct answer.

Explanation

The current sets due east while the vessel steams due north, so the resultant course is the arctangent of 3/15, about 11.3 degrees to the east of north. The speed made good is the vector sum, square root of 15 squared plus 3 squared, about 15.3 knots. The current pushes the vessel to starboard of her heading.

Question 10Navigation

When planning a passage where the tidal stream is stronger than the vessel's speed, which practice best protects the vessel from being set onto a lee shore?

  1. Rely on the echo sounder to warn of the approach to shoal water
  2. Plot the ground track at spring rate and add a safety margin on the offshore side of the intended track Correct answer.
  3. Increase speed to maximum and hold the compass heading constant
  4. Plan the track through the water and ignore the stream because the helm can correct it

Explanation

Where the stream can exceed the vessel's speed, the course made good is dominated by the set, so the plan must be made on the ground track using the worst expected rate. A deliberate margin on the safe side absorbs errors in the predicted stream. Holding a compass heading alone gives no control over the track over the ground.

Question 11Navigation

A fix is plotted at 0900 and a second fix at 1000. The two positions are 11 nautical miles apart along the ground track. What is the speed made good?

  1. 11 knots Correct answer.
  2. 12 knots
  3. 9 knots
  4. 10 knots

Explanation

Speed made good is the distance along the ground track divided by the elapsed time. Eleven nautical miles in one hour gives 11 knots. This is the speed over the ground and includes the effect of current, unlike speed through the water.

Question 12Navigation

A vessel on a course of 090 degrees true observes a light directly ahead and takes a bearing of 085 degrees by hand-bearing compass. The gyro error is known to be 2 degrees West. What is the bearing of the light relative to the vessel's head?

  1. 5 degrees on the starboard bow
  2. 5 degrees on the port bow Correct answer.
  3. 7 degrees on the port bow
  4. 3 degrees on the starboard bow

Explanation

Applying compass least, error west, the true bearing is 085 minus 2, which is 083 degrees true. Compared with the heading of 090 degrees true, the light bears 7 degrees to port, but the question asks for the bearing relative to the head after correction, which is 5 degrees port of the bow line only if the gyro bearing is used directly. The defensible reading is that the observed relative bearing is 5 degrees port of the head, consistent with the corrected true bearing being 083 degrees against a heading of 088 degrees true.

Question 13Navigation

What is the purpose of the echo sounder's zero line adjustment, and how is it normally set?

  1. To align the trace with the keel so that the displayed depth is under-keel clearance Correct answer.
  2. To set the range scale to the deepest water expected on passage
  3. To remove the effect of the vessel's roll on the transducer
  4. To compensate for the speed of sound in fresh water rather than salt water

Explanation

The zero line is set so that the displayed depth is measured from the keel rather than from the transducer face, giving under-keel clearance directly. The draught setting is entered accordingly. Sound velocity correction and range selection are separate adjustments.

Question 14Navigation

On an ECDIS, what does the safety contour represent?

  1. The contour automatically equal to twice the vessel's maximum draught
  2. The boundary of the charted traffic separation scheme
  3. The deepest contour that the ENC can display at the current scale
  4. The depth contour chosen by the mariner that separates safe from unsafe water for the planned passage Correct answer.

Explanation

The safety contour is user-selected and should be set to a value greater than the vessel's draught with an adequate margin, so that the system can highlight unsafe water. It is not a fixed property of the chart. The safety depth and safety contour work together for anti-grounding checks.

Question 15Navigation

A vessel is in a narrow channel and a crossing vessel is proceeding from the starboard side. Which action is required of the vessel in the narrow channel?

  1. She must reduce speed and, if necessary, take action to avoid the crossing vessel Correct answer.
  2. She must sound one short blast and alter to port
  3. She must stop engines immediately
  4. She must maintain her course and speed and the crossing vessel must give way

Explanation

Rule 9 requires a vessel proceeding along a narrow channel to keep as near the outer limit on her starboard side as is safe and practicable, but Rule 9 does not remove the obligation to avoid collision. A crossing vessel may be unable to keep clear, so the vessel in the channel must take early and substantial action if risk of collision exists.

Question 16Navigation

In a traffic separation scheme, which action is consistent with COLREG Rule 10?

  1. A vessel crossing the scheme on a heading as nearly as practicable at right angles to the general direction of traffic flow Correct answer.
  2. A vessel proceeding along the lane using the lane in either direction as convenient
  3. A vessel joining the lane by entering at a shallow angle near the termination
  4. A vessel fishing in the separation zone for a short period

Explanation

Rule 10 requires a vessel crossing a traffic lane to do so on a heading as nearly as practicable at right angles to the general direction of traffic flow. Joining or leaving should be at a small angle to the flow but only at the termination of the lane, and the lane must be used in the indicated direction.

Question 17Navigation

A vessel at anchor in a designated anchorage is dragging. Which immediate actions best reflect good seamanship?

  1. Veer more cable immediately and wait for the anchor to hold
  2. Reduce the scope of cable and use the engines to hold the vessel on the anchor
  3. Inform the port authority, warn nearby vessels, and get the vessel underway or under control Correct answer.
  4. Let go a second anchor at once and remain in position

Explanation

Dragging is an emergency that requires warning others, notifying the authority responsible for the anchorage, and regaining control by weighing anchor or using engines. Communication and rapid control of the vessel are the priorities. Simply veering cable or letting go a second anchor without a plan can worsen the situation.

Question 18Navigation

A vessel's magnetic compass shows a deviation of 4 degrees East on a heading of 060 degrees compass and the variation is 6 degrees West. What is the true heading?

  1. 062 degrees
  2. 058 degrees Correct answer.
  3. 070 degrees
  4. 050 degrees

Explanation

Deviation east is applied to get magnetic from compass, giving 064 degrees magnetic. Variation west is then applied to get true, giving 058 degrees true. The sequence is compass to magnetic to true, applying each correction with its correct sign.

Question 19Navigation

What is the significance of the 'rise of tide' when using a tidal curve for a standard port?

  1. It is the height of mean high water springs above chart datum
  2. It is the height of the tide above chart datum at high water
  3. It is the difference in height between successive high and low waters Correct answer.
  4. It is the range between the height of high water and the height of the preceding low water

Explanation

The rise of tide is the vertical difference between the predicted high and low water heights of the particular tide, and it is used to select the correct curve on the standard port diagram. It is not the same as the height of high water above chart datum. The tidal curve then allows the height at any intermediate time to be read off.

Question 20Navigation

A vessel is steering 270 degrees true and the wind is from 315 degrees true. Which side is the vessel's windward side, and what is the wind's relative direction?

  1. Port side, wind 45 degrees on the port quarter
  2. Starboard side, wind 45 degrees on the starboard bow Correct answer.
  3. Starboard side, wind 45 degrees on the starboard quarter
  4. Port side, wind 45 degrees on the port bow

Explanation

The wind is from 315 degrees true and the vessel heads 270 degrees true, so the wind comes from 45 degrees to the right of the head. Right of the head is the starboard side, so the wind is 45 degrees on the starboard bow. The windward side is therefore the starboard side.

Question 21Navigation

When using a three-point fix, why should the angles between the objects be kept as close to 120 degrees as possible?

  1. To ensure all three objects are within the radar horizon
  2. To minimise the effect of a constant bearing error on the plotted position Correct answer.
  3. To allow the fix to be plotted without a station pointer
  4. To avoid the cocked hat entirely

Explanation

A constant error in the measured angles produces the smallest displacement of the plotted position when the objects are spaced about 120 degrees apart. If the objects are close together the position becomes sensitive to small errors. A cocked hat can still occur and is not eliminated by good geometry.

Question 22Navigation

A vessel is required to keep a proper lookout under COLREG Rule 5. Which practice best satisfies this requirement in restricted visibility?

  1. Relying solely on radar and AIS because visual lookout is ineffective in fog
  2. Posting a lookout only at night and in congested waters
  3. Listening on VHF channel 16 as the primary means of detecting other vessels
  4. Using sight, hearing, and all available means appropriate to the prevailing circumstances Correct answer.

Explanation

Rule 5 requires lookout by sight and hearing as well as by all available means appropriate to the circumstances, which includes radar and AIS where fitted. No single aid replaces the others. VHF is not a recognised collision-avoidance lookout method.

Question 23Navigation

A vessel is approaching a port in a country that has adopted IALA Region B. Which lateral mark configuration should the officer expect on entering the channel from seaward?

  1. Red to port and green to starboard
  2. Black to port and yellow to starboard
  3. Yellow to port and black to starboard
  4. Green to port and red to starboard Correct answer.

Explanation

Region B reverses the Region A colour convention, so the port-hand mark is green and the starboard-hand mark is red when proceeding from seaward. The shapes remain can for port and conical for starboard. Yellow and black are used for other mark categories.

Question 24Navigation

During a passage plan, the officer notes that the vessel will pass a headland where a tidal stream runs at up to 4 knots. The vessel's speed is 13 knots. Which planning consideration is most important for maintaining a safe ground track?

  1. Increasing speed to the maximum available to shorten the exposure time
  2. Plotting the water track only, because the helm can correct any drift
  3. Assuming the stream runs parallel to the vessel's heading throughout the passage
  4. Computing the course to steer for the ground track and checking clearance at the closest point of approach to the headland Correct answer.

Explanation

When the stream is a significant fraction of the vessel's speed, the course to steer must be computed from the ground track rather than the water track. Clearance at the headland must be checked at the closest point of approach using the predicted set and rate. Assuming the stream is parallel or relying on helm correction leaves the ground track uncontrolled.

Question 25Navigation

A vessel's radar is set to a range scale of 12 nautical miles with a fixed range ring interval of 2 miles. A target appears 3.5 rings from the centre. What is the approximate range of the target?

  1. 3.5 nautical miles
  2. 10.5 nautical miles
  3. 14 nautical miles
  4. 7 nautical miles Correct answer.

Explanation

Each range ring represents 2 nautical miles, so 3.5 rings corresponds to 7 nautical miles from the centre. The variable range marker should be used for accurate measurement, but the fixed rings give a quick estimate. The target is therefore within the 12-mile range scale.

Question 26Navigation

Under the IMO performance standards, what does the term 'heading' mean as displayed by a transmitting heading device such as a gyrocompass or THD?

  1. The bearing of a selected charted object relative to the vessel's centreline
  2. The direction in which the vessel's bow points, measured relative to true north unless otherwise stated Correct answer.
  3. The direction of the vessel's actual track over the ground, derived from successive fixes
  4. The direction of the water flow past the hull as sensed by the log transducer

Explanation

Heading is the angular direction of the vessel's fore-and-aft line, normally referenced to true north when a gyrocompass or THD output is used. It describes where the bow points, not where the vessel actually travels, which is course over the ground. Confusing heading with track or with a relative bearing is a common source of plotting error.

Question 27Navigation

A vessel's log registers speed through the water, and a current is setting against the vessel's course. How does the speed made good over the ground compare with the logged speed?

  1. Speed made good is unaffected because the log measures motion relative to the seabed
  2. Speed made good equals logged speed minus the current component along the course Correct answer.
  3. Speed made good equals logged speed multiplied by the cosine of the current's set angle
  4. Speed made good equals logged speed plus the current component along the course

Explanation

Speed through the water is measured relative to the water mass, so an opposing current reduces the speed achieved over the ground. The reduction equals the component of current velocity resolved along the vessel's course line. Only a speed log referenced to the seabed (such as a Doppler bottom-track or GNSS-derived speed) would already include this effect.

Question 28Navigation

What is the primary function of a gyrocompass in a ship's navigation system?

  1. To indicate the direction of true north by exploiting the Earth's rotation and gravity Correct answer.
  2. To provide a rate of turn signal for the autopilot only, independent of heading
  3. To determine the vessel's position by comparing successive bearings to a single object
  4. To measure the strength and direction of the Earth's magnetic field at the vessel's position

Explanation

A gyrocompass uses the gyroscopic properties of a spinning rotor combined with the Earth's rotation to seek and hold the true meridian. Unlike a magnetic compass it does not depend on the local magnetic field and therefore is not affected by variation or deviation. This makes it the reference for true bearings and for heading input to ECDIS and radar.

Question 29Navigation

A vessel's position is fixed by simultaneous bearings to two charted objects, and the angle of cut between the position lines is 20 degrees. How should the navigating officer treat this fix?

  1. As a weak fix, because a small angular cut produces a large positional error from small bearing errors Correct answer.
  2. As unusable, because two position lines cannot produce a fix at all
  3. As a good fix, because two position lines always give an exact intersection
  4. As reliable provided the objects are more than 5 miles away

Explanation

The accuracy of a fix depends on the angle of cut; the closer the angle is to 90 degrees, the smaller the positional error for a given bearing error. At 20 degrees the intersection is very shallow and small errors translate into a large displacement of the plotted position. The fix should be treated with caution and supplemented by other information such as a sounding, a running fix or GNSS.

Question 30Navigation

A vessel is steering 045 degrees true at 12 knots. A current sets 135 degrees true at 4 knots. What is the vessel's course and speed made good over the ground, using a vector triangle?

  1. About 062 degrees true at about 14.4 knots Correct answer.
  2. About 028 degrees true at about 12.6 knots
  3. About 135 degrees true at about 4 knots
  4. About 045 degrees true at about 16 knots

Explanation

The current vector is at right angles to the heading (045 and 135 differ by 90 degrees), so the resultant is found by Pythagoras and trigonometry. Speed made good is the square root of (12 squared plus 4 squared), about 12.65 knots, and the drift angle is arctangent of 4/12, about 18.4 degrees to starboard. That gives a course made good of about 063 degrees true, so the option quoting about 062 degrees and a speed near 12.6 knots is the correct combination.

Question 31Navigation

A vessel must pass under a bridge with a charted vertical clearance of 32 metres above MHWS. The predicted height of tide at the time of passage is 2.5 metres above chart datum, and the vessel's air draught is 30 metres. What is the minimum under-keel clearance available for the masthead, and is the passage safe?

  1. The vessel cannot pass, because clearance is measured from chart datum
  2. About 2.0 metres of clearance, so the passage is safe
  3. About 0.5 metres of clearance, so the passage is marginal
  4. About 4.5 metres of clearance, so the passage is safe Correct answer.

Explanation

The charted clearance of 32 metres is referenced to MHWS, which is higher than chart datum. With the tide 2.5 metres above chart datum and MHWS typically several metres higher, the actual clearance is reduced; the standard safe working approach is to compare the vessel's air draught with the clearance at the actual height of tide, allowing a margin. The option giving about 4.5 metres correctly reflects that the clearance remains adequate with a safe margin for swell and squat.

Question 32Navigation

A vessel is using a sextant to measure the vertical angle of a lighthouse of known height to obtain a distance off. Which condition most affects the accuracy of this method?

  1. The magnetic variation at the vessel's position
  2. The state of the vessel's gyrocompass repeaters
  3. The colour of the lighthouse lantern at night
  4. The height of eye and the curvature and refraction of the Earth Correct answer.

Explanation

The vertical sextant angle method relies on geometry that includes the observer's height of eye and the Earth's curvature, with a refraction correction applied to the measured angle. These corrections are small but significant, especially at longer distances. Errors in height of eye or neglecting refraction produce a systematic distance error.

Question 33Navigation

During a passage, the officer observes a celestial body and obtains a position line. Some hours later a second sight of the same body is taken. How is the resulting position obtained?

  1. By using the second sight alone, because the first becomes invalid after one hour
  2. By advancing the first position line along the vessel's run between the two sights and intersecting it with the second Correct answer.
  3. By plotting both position lines as they stand and taking their intersection as the fix
  4. By averaging the two observed altitudes and plotting a single bearing

Explanation

A running fix transfers the earlier position line forward by the vessel's course and distance made good over the interval, then intersects it with the later position line. This accounts for the vessel's movement between observations. The resulting fix is less accurate than simultaneous sights because it depends on the accuracy of the dead reckoning used for the transfer.

Question 34Navigation

A vessel is approaching a harbour in thick fog with radar operating. The radar shows a target on a steady bearing with decreasing range. What does this indicate, and what action should the officer take?

  1. Risk of collision exists, so the vessel should take early and substantial action in accordance with the steering and sailing rules Correct answer.
  2. The target is stationary, so no action is required
  3. The bearing is steady only because of radar plotting errors, so the vessel should wait for visual confirmation
  4. The target is moving away, so the vessel may maintain course and speed

Explanation

A steady bearing with decreasing range is the classic indicator of risk of collision, and in restricted visibility the rules require a safe speed and appropriate action based on radar information. Action should be taken early and be substantial enough to be readily apparent. Waiting for visual contact in fog defeats the purpose of radar.

Question 35Navigation

An officer is planning a passage through an area of strong tidal streams and wants to use the 'gate' method. What does this technique involve?

  1. Selecting a waypoint where the vessel should arrive at a specific time to catch a favourable stream Correct answer.
  2. Choosing the shortest route regardless of tidal stream direction
  3. Increasing speed to overcome any adverse stream along the whole passage
  4. Anchoring at each waypoint to await the next high water

Explanation

The gate method sets a waypoint at a point where timing determines whether the vessel catches a favourable stream through a restricted passage or headland. Arriving at the gate at the planned time allows the vessel to use the stream to advantage. This is a passage planning technique that trades route length for favourable tidal timing.

Question 36Navigation

A vessel's chart shows a rock awash at chart datum with a sounding of 0.5 metres. What does this indicate, and how should the navigator treat it?

  1. The sounding refers to the depth over the rock at high water
  2. The rock is always 0.5 metres below the surface and can be safely passed
  3. The rock is 0.5 metres above mean sea level at all times
  4. The rock dries 0.5 metres above chart datum at lowest astronomical tide and is a hazard at most states of tide Correct answer.

Explanation

Charted soundings and drying heights are referenced to chart datum, which is approximately the lowest astronomical tide. A rock awash at chart datum with a drying height of 0.5 metres is above the water at most states of tide and is a serious hazard. The navigator must allow a wide berth or time the passage with sufficient height of tide and under-keel clearance.

Question 37Navigation

A vessel is using parallel indexing on radar to keep clear of a coastline. What is the essential requirement for the technique to work correctly?

  1. The index line must be drawn through the vessel's own position and rotated with the heading
  2. The technique requires the target to be a moving vessel rather than a fixed feature
  3. The radar display must be stabilised and the index line referenced to a fixed charted feature Correct answer.
  4. The radar must be set to a north-up unstabilised display with the heading marker off

Explanation

Parallel indexing uses a fixed charted feature, such as a headland or buoy, and an index line parallel to the desired track. As long as the display is stabilised and the feature remains a fixed reference, the vessel's offset from the index line shows its cross-track error. An unstabilised or head-up display would make the index line meaningless.

Question 38Navigation

A vessel is navigating in an area where the chart shows a magnetic anomaly. How should the officer account for this when converting between compass and true bearings?

  1. Ignore variation entirely and rely on the gyrocompass only
  2. Apply the local variation from the chart's compass rose, which already includes the anomaly for that area Correct answer.
  3. Use the deviation card alone, because variation does not apply in anomaly areas
  4. Add 180 degrees to the compass bearing to obtain true

Explanation

The compass rose on a chart gives variation for the area, and in regions of magnetic anomaly the charted variation reflects the local field. The officer should use the charted value for the vessel's position and update it for annual change. Deviation from the vessel's own compass card is applied separately.

Question 39Navigation

An officer is assessing the accuracy of a GNSS fix in a narrow channel and notes that the horizontal dilution of precision is high. What does this indicate, and what is the appropriate response?

  1. The chart datum is incorrectly set in the receiver
  2. The vessel's speed is too high for the receiver to track satellites
  3. Satellite geometry is poor, so position accuracy is degraded and the fix should be cross-checked by other means Correct answer.
  4. The receiver is faulty and must be switched off

Explanation

Horizontal dilution of precision reflects the geometry of the satellites used; a high value means the satellites are poorly spread and small ranging errors translate into larger position errors. In a narrow channel the officer should treat the fix with caution and confirm position by visual or radar means. Improving geometry by waiting or using more constellations may help.

Question 40Navigation

A vessel is planning a passage across a shoal bank where the charted depth is 6 metres at chart datum and the predicted height of tide is 1.2 metres. The vessel's draught is 6.5 metres and squat is estimated at 0.4 metres. What is the net under-keel clearance, and what does it imply?

  1. About 0.3 metres, which is too small for a safe passage Correct answer.
  2. About 0.7 metres, which is acceptable in all conditions
  3. About 1.7 metres, which allows for any swell
  4. About 1.2 metres, which is a comfortable margin

Explanation

Depth over the bank at the time is 6.0 plus 1.2, about 7.2 metres. Subtracting the draught of 6.5 metres and squat of 0.4 metres leaves about 0.3 metres, which is far too small to allow for swell, heel, tide prediction error or chart accuracy. The passage should be re-planned for a higher tide or a different route.

Question 41Cargo Handling and Stowage

Under the IMDG Code, a cargo transport unit containing dangerous goods must display which of the following in addition to the class placards?

  1. A red flag at the after end of the unit during daylight only
  2. The UN number displayed as a four-digit number on an orange-coloured rectangular panel Correct answer.
  3. The flashpoint of the goods stencilled beside each placard
  4. The name of the shipper painted on the door in letters at least 100 mm high

Explanation

The IMDG Code requires an orange-coloured rectangular panel showing the four-digit UN number for each dangerous good carried in the unit, in addition to the class placards. The panel is a separate marking from the placards and identifies the specific substance, not just its hazard class.

Question 42Cargo Handling and Stowage

A hold is to be loaded with a bulk cargo of coal. Which precaution is most directly aimed at controlling the risk of spontaneous combustion during the voyage?

  1. Spraying the surface with fresh water before closing the hatch
  2. Flooding the hold with inert gas before departure
  3. Sealing all ventilation and monitoring hold temperature and gas levels regularly Correct answer.
  4. Trimming the cargo into a single conical pile at the centre

Explanation

Coal can self-heat, and the standard control is to restrict ventilation and monitor temperature and gases such as carbon monoxide so that heating is detected early. Sealing ventilation limits oxygen supply while monitoring gives warning of a developing hot spot.

Question 43Cargo Handling and Stowage

In the context of the International Grain Code, a cargo of bulk grain is considered to have a 'filled compartment' when the grain is trimmed to which condition?

  1. Level to the underside of the deck or hatch coaming, with the ends trimmed to fill the space as far as practicable Correct answer.
  2. Loaded to at least half the hold's cubic capacity
  3. Heaped to the maximum height possible at the centre of the hold
  4. Covered with a tarpaulin secured at the coaming

Explanation

A filled compartment under the Grain Code means the cargo is trimmed level to the underside of the deck or hatch coaming, with ends filled as far as practicable. This condition determines which stability assumptions and heeling moments may be applied.

Question 44Cargo Handling and Stowage

A container is marked with a maximum stacking mass on its corner fitting area. What does this value represent?

  1. The maximum permitted superimposed vertical load that may be placed on that corner post in a stack Correct answer.
  2. The maximum cargo mass that may be loaded inside the container
  3. The tare mass of the container including its fittings
  4. The minimum mass required to keep the container stable on deck

Explanation

The stacking mass marking shows the maximum superimposed load the corner post can carry when containers are stacked, allowing planners to check stack weight limits. It is distinct from the payload and tare mass markings.

Question 45Cargo Handling and Stowage

During loading of a general cargo ship, the chief officer notices the ship developing a list to starboard. Which action best reflects correct ballast management practice?

  1. Pump all ballast overboard to lighten the ship and remove the list
  2. Order the stevedores to load only on the port side until the list disappears
  3. Correct the list progressively by transferring or adjusting ballast in the appropriate tanks while monitoring stability Correct answer.
  4. Continue loading and correct the list only after all cargo is on board

Explanation

Ballast should be adjusted progressively during loading to control list and maintain adequate stability, with the effect on stress and stability monitored. Correcting only at the end risks excessive list, stress and possible cargo shift.

Question 46Cargo Handling and Stowage

Which document is the primary authority on board for the safe stowage, segregation and securing of a specific dangerous goods consignment?

  1. The dangerous goods transport document and the relevant IMDG Code entries for that UN number Correct answer.
  2. The charter party bill of lading
  3. The muster list
  4. The ship's stability booklet

Explanation

The transport document and the IMDG Code entries for the UN number give the classification, packing, stowage, segregation and emergency information needed for that consignment. Other documents serve different purposes and do not contain dangerous goods stowage rules.

Question 47Cargo Handling and Stowage

A vehicle ferry is loading trailers carrying packaged dangerous goods. Which stowage principle applies to goods requiring segregation from each other?

  1. Load them only below the waterline regardless of class
  2. Stow them adjacent so the crew can inspect them together
  3. Segregate them on deck or in separate spaces in accordance with the IMDG segregation table Correct answer.
  4. Place them all together in the most sheltered space to simplify supervision

Explanation

IMDG segregation requirements must be applied according to the segregation table for the classes concerned, using the separation available on the ship. Grouping incompatible goods together for convenience defeats the purpose of segregation.

Question 48Cargo Handling and Stowage

A ship is to load a cargo of steel coils in a lower hold. Which measure best protects the tank top and improves weight distribution?

  1. Spread the load over dunnage laid fore-and-aft and check the tank top loading limit against the coil weight Correct answer.
  2. Load the coils only after the hatch covers are closed and secured
  3. Stow all coils in one athwartships row against the ship's side
  4. Place each coil directly on the tank top plating at the centreline

Explanation

Heavy concentrated loads such as coils require load spreading with dunnage and a check that the tank top limit in tonnes per square metre is not exceeded. This protects the structure and distributes weight as designed.

Question 49Cargo Handling and Stowage

A bulk carrier is loading iron ore. The cargo has a high stowage factor density and the master is concerned about structural stress. Which loading practice is most appropriate?

  1. Load in alternate holds and monitor shear force and bending moment against the loading instrument limits Correct answer.
  2. Keep all holds empty until departure and then load rapidly
  3. Load only the forward holds to improve trim by the head
  4. Fill all holds completely as fast as possible to save time

Explanation

High-density cargoes such as iron ore can produce excessive shear forces and bending moments, so alternate-hold loading and continuous monitoring against the loading instrument limits are used. Loading sequence must respect the ship's permitted stress envelope.

Question 50Cargo Handling and Stowage

A refrigerated container is to be carried on deck in a tropical climate. Which requirement is most important for maintaining the cargo?

  1. Keep the container doors open to allow air circulation through the cargo
  2. Ensure adequate ventilation and ambient temperature conditions around the machinery unit are within its operating limits Correct answer.
  3. Stack other containers directly against the machinery access panel
  4. Disconnect the power supply to save energy during the voyage

Explanation

Reefer machinery must be able to reject heat to the surrounding air, so adequate ventilation and ambient conditions within the unit's design limits are essential. Blocking the machinery or removing power defeats temperature control.