Egypt Maritime COC Deck common mistakes
Egypt Maritime COC Deck · Understand the traps and how to avoid them.
When computing a celestial line of position, plotting the intercept using the observed altitude minus the computed altitude but applying it in the wrong direction along the azimuth (plotting 'away' when the intercept is 'towards', or vice versa), so the resulting fix is displaced by twice the intercept and the cocked hat does not close.
Candidates memorise 'Ho - Hc' but lose track of the sign convention under exam pressure, especially when the intercept is negative or when converting from an assumed position to a DR-based plot. Many have practised only with positive intercepts.
What to do instead
Adopt a fixed written routine: always write Ho, Hc, and the signed difference; if Ho > Hc the intercept is Towards (T) and is plotted from the assumed position along the azimuth toward the GP; if Ho < Hc it is Away (A). Practise five sight reductions deliberately including negative intercepts, and after plotting each LOP sanity-check that the fix lies between the assumed position and the GP when intercepts are Towards.
Applying magnetic variation and deviation with the wrong sign when converting between true, magnetic and compass courses, e.g. subtracting westerly variation when going from compass to true, or adding easterly deviation when going from true to compass.
The mnemonic 'Can Dead Men Vote Twice At Elections' is remembered but the direction of application is confused; candidates also mix up variation (chart, geographic) with deviation (ship-specific, from the deviation card) and forget that deviation depends on the ship's heading.
What to do instead
Write the conversion table on the working paper every time: Compass, Deviation, Magnetic, Variation, True, with 'add easterly, subtract westerly' applied consistently in the direction of travel. Work one example in each direction (C to T and T to C) and verify by reversing the calculation. Always look up deviation for the actual compass heading, not the true heading.
Answering COLREG questions with a general principle ('give way to starboard', 'the bigger ship keeps clear') instead of citing the specific rule, the specific lights/shapes exhibited, and the specific action required, and failing to state the give-way vessel's obligation to take early and substantial action.
Candidates study the rules as prose rather than as decision trees, so under time pressure they reason from intuition. Crossing, overtaking and head-on situations are also confused when the aspect is ambiguous or when a vessel is constrained by draught or engaged in fishing.
What to do instead
For every encounter question, answer in a fixed four-part structure: (1) rule number and situation type; (2) which vessel is give-way and which is stand-on, and why (aspect/relative bearing); (3) the lights and shapes each vessel exhibits; (4) the action required, including 'early and substantial' for the give-way vessel and the stand-on vessel's duty to hold course and speed but take action if collision cannot be avoided by the give-way vessel alone. Drill the crossing, head-on, overtaking and narrow-channel rules until the structure is automatic.
Calculating free surface effect and its correction to GM by using the wrong formula, for example applying FSC = i x ρ / (Δ) without dividing by the displacement in the correct units, or forgetting to subtract FSC from KM - KG to get the effective GM, and then declaring the vessel stable when the corrected GM is small or negative.
The free surface correction is a small number easily lost in unit conversions (tonnes, cubic metres, metres), and candidates confuse the second moment of area of the tank surface with the tank volume. They also forget that FSC is independent of the amount of liquid and depends only on the tank dimensions and the liquid density.
What to do instead
Write the formula with units attached: FSC (m) = (i x ρ_liquid) / (Δ x ρ_water), where i = l x b^3 / 12 for a rectangular tank. Compute the uncorrected GM = KM - KG first, then subtract FSC to obtain the effective GM, and state both values in the answer. Check the order of magnitude: for a typical cargo ship FSC is a few centimetres, not metres. Practise with a part-filled rectangular double-bottom tank and a slack hold.
Planning a cargo stowage plan without checking the load line zone limits, the permissible deck load, or the segregation requirements for dangerous goods, and presenting a plan that is within deadweight but exceeds the summer draught or violates IMDG segregation.
Candidates focus on the arithmetic of deadweight and volume and treat regulatory limits as an afterthought. They also misapply the IMDG segregation table (e.g. treating 'separated from' and 'separated by a complete compartment or hold from' as the same requirement).
What to do instead
Build a checklist that must be completed before the plan is submitted: (1) load line zone for the voyage dates and route, and the corresponding permitted draught; (2) deadweight, trim and stability check; (3) hatch and deck load limits; (4) IMDG class, segregation code and stowage category for every dangerous goods entry, quoting the table row used. State the segregation code you applied and why, rather than asserting segregation is 'adequate'.
Confusing the damage control measures for a hull breach: ordering counter-flooding to correct list when the correct first action is to close watertight doors and establish the extent of flooding, or plugging a hole without shoring, and failing to distinguish progressive flooding from a contained compartment.
Candidates memorise a list of damage control actions without understanding the sequence and the stability consequences; counter-flooding a damaged ship can reduce reserve buoyancy and worsen the situation if the flooding is not yet contained.
What to do instead
Answer in the correct sequence: sound the alarm and muster; close watertight doors and hatches to limit spread; assess the extent of flooding (sounding, visual, stability calculation); then decide on counter-flooding only when the flooding is contained and the free surface and reserve buoyancy consequences have been calculated. State the effect of each action on GM, list and reserve buoyancy. Know the difference between a collision bulkhead, a watertight bulkhead and a tank boundary.
Reading a synoptic chart or forecast and describing the weather without interpreting the isobar spacing, the position of the front relative to the vessel, and the expected wind shift, so the answer gives a general 'strong winds expected' instead of a specific forecast of wind direction, force and timing.
Candidates can name the symbols but have not practised deriving local wind from pressure gradient and Buys Ballot's law, or tracking a frontal passage; they also confuse the direction of movement of a depression with the wind circulation.
What to do instead
For every chart question, state: (1) the pressure gradient from isobar spacing and the resulting wind force; (2) the wind direction using Buys Ballot's law (back to wind in the Northern Hemisphere, face the wind in the Southern Hemisphere); (3) the front's position and expected passage time, with the associated wind veer/backing and visibility change; (4) the sea state and any warning (gale, storm, tropical revolving storm). Practise with two contrasting charts, one Northern and one Southern Hemisphere.
In GMDSS questions, selecting the wrong distress priority or the wrong device: sending a DSC distress alert on VHF channel 70 and then failing to follow with a distress call on channel 16, or using a non-GMDSS frequency for a Mayday, or confusing the functions of EPIRB, SART and NAVTEX.
Candidates learn the equipment names but not the operational sequence and the frequency/priority conventions; the distinction between the alerting function (DSC, EPIRB) and the locating function (SART) is blurred.
What to do instead
Learn the alerting sequence as a script: VHF DSC distress alert on channel 70 with the correct distress priority, then a Mayday voice call on channel 16 with the vessel's identity, position, nature of distress and assistance required. Know that the EPIRB alerts via satellite (406 MHz) and the SART responds on 9 GHz radar. Know NAVTEX frequencies and that it carries MSI, not distress alerting. Practise writing out a complete Mayday and a complete urgency (Pan Pan) message.
Answering maritime law questions by describing what 'should' happen operationally rather than identifying the applicable convention or statute, the obligation of the master, and the reporting/notification chain (flag State, port State, coastal State, owner, P&I club).
Candidates treat law as common sense and do not distinguish between SOLAS, MARPOL, COLREG, STCW and UNCLOS obligations, or between the master's authority and the company's responsibility under the ISM Code.
What to do instead
For each legal scenario, name the instrument and the specific obligation: e.g. MARPOL Annex I discharge restrictions and the oil record book; SOLAS V reporting requirements; UNCLOS Article 98 duty to render assistance; ISM Code reporting to the company. Then state the notification chain in order and the records that must be kept. Learn the difference between flag State, port State and coastal State jurisdiction.
In search and rescue questions, choosing a search pattern without reference to the datum, the elapsed time, the search object and the available units, or failing to state the on-scene coordinator's responsibilities and the communications plan.
Candidates memorise pattern names (expanding square, sector, parallel sweep, creeping line) but not the selection criteria; they also omit the datum update as time passes and the effect of leeway and drift.
What to do instead
Answer with the selection logic: establish and plot the datum, apply leeway and drift for the elapsed time, then choose the pattern based on the search object, the size of the area and the number of units (expanding square for a small area around a known datum, parallel sweep for a large area, sector search for a man overboard with a known datum). State the OSC's duties: coordinate units, assign search areas, maintain communications, and report to the RCC. Include the communications plan and the datum update interval.