Coastguard NZ Day Skipper common mistakes
Coastguard NZ Day Skipper · Understand the traps and how to avoid them.
Reading a charted depth as the actual depth of water under the keel, so a passage is planned over a 3 m charted bank in a boat drawing 1.5 m without adding the height of tide.
Candidates learn 'soundings show depth' as a slogan and never convert the chart's Lowest Astronomical Tide datum into the water actually present at the time of passage, or they forget that chart soundings are drying heights in italics and negative.
What to do instead
Drill the fixed formula every time: depth available = charted depth + height of tide − draught − safety margin. Practise on a real chart by picking three soundings, looking up the tide height for that hour, and writing the arithmetic out in full rather than estimating. Check drying heights (underlined figures) are subtracted, not added.
Applying the rule of twelfths to the wrong reference point, for example measuring the rise from high water rather than low water, or using the range for the wrong day, producing a tide height that is out by a metre or more.
The rule is learned as a sequence (1,2,3,3,2,1) without anchoring it to 'the first twelfth is measured from low water towards high water'. Candidates also grab the spring range when the passage falls on a neap day, or use the standard port figure for a secondary port without applying the differences.
What to do instead
Always sketch the tide curve: mark LW and HW, label the range, then divide the time into sixths counting forward from LW. State the range used and where it came from (which day, which port, standard or secondary). Rehearse secondary port differences (time and height) until the order of operations is automatic.
Plotting a course to steer or a position fix using the wrong convention - measuring bearing from the boat to the mark instead of from the mark to the boat, or plotting a reciprocal, or reading the compass rose outer ring (true) when the hand bearing compass reads magnetic.
Hand bearing compass readings are magnetic while the chart is graduated in true, and the variation must be applied in the correct direction. Under time pressure candidates skip the 'cadet' memory aid and add when they should subtract.
What to do instead
Write the conversion on the plot: 'True Virgins Make Dull Company - Add Whiskey' (True + Variation = Magnetic, add westerly). Practise ten conversions each way until error-free. For position fixes, always draw the bearing line back from the identified object towards your own vessel and sanity-check that the fix lands on the water, not inland.
Treating a GPS position or chartplotter track as the navigation answer, without a paper plot, a dead reckoning position, or any check that the GPS datum matches the chart datum.
Plotters are easy and confidence-inspiring, and candidates assume the exam only wants the electronic answer. They also do not know that a WGS84 position plotted on a chart with a different datum can be displaced by hundreds of metres.
What to do instead
Maintain a running DR and a fix at least every hour, and cross-check the GPS against a visual fix when marks are available. Know which datum the chart uses and set the GPS to match. In the exam, show the paper working even when the GPS figure is given.
Giving a Mayday or Pan Pan call that omits the vessel's position, or gives it as a street address or 'near the harbour', and then releasing the microphone before the coastguard has acknowledged.
Candidates rehearse the word order but freeze on the one item that is not memorised. They also treat the call as a broadcast rather than a two-way exchange, and do not wait for the 'Mayday received' acknowledgement before continuing.
What to do instead
Learn the position formats accepted: latitude and longitude, bearing and distance from a named point, or a charted feature. Practise the full call aloud with a stopwatch, including a deliberate pause after the position for acknowledgement. Remember the priority sequence: Mayday, this is, vessel name and callsign repeated three times, then position, nature of distress, assistance required, persons on board.
Using the wrong channel or transmitting without checking it is free - calling on channel 16 for a routine chat, using channel 16 for a long exchange, or failing to switch to a working channel after the initial call.
Channel 16 is the only channel candidates remember, so it becomes the default. They do not know that routine traffic should move to a working channel (for example 68, 71 or 72 in New Zealand waters) and that channel 16 is for distress, urgency, safety and calling only.
What to do instead
Memorise the practical set: 16 for distress and calling, a nominated working channel for the conversation, VHF channel 16 silence periods respected. Practise the pattern 'call on 16, agree a working channel, switch, conduct business, return to 16'. Know that channel 70 is DSC only and must never carry voice.
Underestimating stopping distance and the effect of wind and current when approaching a berth or a mooring, arriving too fast and then using reverse as a brake.
On a calm training day the boat stops quickly and steers predictably. Candidates carry that feel into wind and tide, and do not account for prop walk, the time reverse takes to bite, or the fact that a planing hull carries way.
What to do instead
Plan every approach: identify wind and current direction, choose the side to come alongside, and aim to arrive with steerage way only. Practise a 'no-reverse' approach where the boat is slowed by planning the angle and using neutral, so reverse is a correction rather than the plan. Learn the prop walk direction of the training boat and use it deliberately.
Leaving the kill cord or engine cut-off lanyard unattached, or wearing an inadequate lifejacket, during the practical handling assessment.
Candidates treat these as box-ticking formalities done at the dock rather than continuous behaviours, and a lifejacket worn unfastened or with a crotch strap missing passes a glance but fails the intent.
What to do instead
Make the pre-start drill physical and verbal: lanyard attached to the driver, lifejacket on and fastened, kill switch tested, crew briefed. Treat the lanyard as part of starting the engine, not a separate task, and check it again after any crew change.
Answering collision-regulation and right-of-way questions from intuition ('the bigger boat gives way', 'power gives way to sail always') rather than the rules.
Everyday courtesy and size hierarchy feel like seamanship, so candidates never learn the exceptions - a power vessel must give way to a vessel engaged in fishing or restricted in ability to manoeuvre, a sailboat overtaking a powerboat must keep clear, and a vessel running downwind versus close-hauled matters in sail-versus-sail encounters.
What to do instead
Learn the hierarchy as a ladder: not under command, restricted in ability to manoeuvre, constrained by draught, fishing, sailing, power. Then apply the specific rules: overtaking vessel keeps clear regardless of type, head-on both alter to starboard, crossing give way to the vessel on your starboard side. Work through ten written scenarios and justify each answer by rule number.
Skipping the pre-departure brief and float plan - no weather check, no one ashore told of the trip, no head count or lifejacket check before leaving the berth.
Candidates see these as paperwork that the skipper does 'later', and the exam's foundation-level questions reward knowing the boat's equipment over knowing the departure routine. In practice the brief is the cheapest safety action available and is examined as such.
What to do instead
Use a fixed, spoken checklist before every departure: forecast and tide checked, float plan left with a responsible person including return time and action if overdue, crew briefed on lifejackets, kill cord, VHF channel and man-overboard drill, fuel and bailer checked. Rehearse it until it takes under two minutes and say it aloud so an examiner can hear the reasoning.