10 frequent mistakes on the skipper exam

1. Confusion with variation and deviation

Candidates often mix up the sign of the corrections: add or subtract variation. The simple rule: going from true to compass — apply corrections with a minus sign; from compass to true — with a plus. Mnemonic: “CADET” (Compass → Add East, Deduct East, Magnetic) — but better still, draw a table once and use it every time.

2. Wrong tack identification

The tack is determined by the side the wind hits the sail. If the wind hits the port side — port tack. The mistake: looking at the boom (where it points) and getting confused. The boom points to the opposite side — that is why on a port tack the boom is to starboard.

3. Memorising lights without understanding

Instead of memorising every vessel type, learn the system: masthead white (forward) 225°, stern white 135°, sidelights red and green at 112.5° each. Everything else (an all-round yellow, red over green for a trawler, three reds in a vertical line for NUC) is an addition to the base. Once you grasp the sector geometry, any question is solved by logic.

4. Tides without the rule of twelfths

“What is the height of water 3 hours after low water?” seems easy outside the exam, but under stress people forget the rule: 1/12, 2/12, 3/12, 3/12, 2/12, 1/12 — that is how the rise (or fall) of water spreads across the cycle’s hours. The first hour rises slowly, the middle quickly, the end slowly again.

5. Speed through water vs speed over ground

When plotting a course allowing for current, candidates confuse SOG (speed over ground) and STW (speed through water). The log shows STW, GPS shows SOG. The vector triangle is built from STW with the current vector, the result is SOG and the COG. The exam directly checks that you understand the difference.

6. Anchor without computing the chain length

Standard: payed-out chain length = 3–5× depth in calm weather, 5–7× in wind, 7–10× in storm conditions. Depth is calculated taking the tide into account (maximum depth under the keel + waterline-to-fairlead). Candidates often consider only the current depth and end up with a vessel that drags as the tide rises.

7. MOB without a clear algorithm

On the question “actions for a man overboard” there must be a memorised sequence: shout “Man overboard!”, assign a spotter, throw a lifebuoy with light and dye, hit MOB on the GPS, switch on VHF channel 16, turn for the chosen recovery method (Quick Stop for sailing, Williamson Turn for power in restricted visibility). Without an algorithm — confusion.

8. Misused VHF

Channel 16 is for calls and distress only. After establishing contact you must move to a working channel (typically 6, 8, 72). Distress signal — MAYDAY MAYDAY MAYDAY, urgency — PAN PAN, safety — SECURITE. Candidates jumble the MAYDAY message order: vessel NAME, position, nature of distress, number of persons, assistance required.

9. Forgotten rule 17

The stand-on vessel also has duties. If it becomes obvious the other is not giving way, the stand-on must take its own action — but not turn to port if the other vessel is on its port side. Many think the stand-on simply keeps going as is, and lose marks on situational questions.

10. Panic and bad timing

The most painful mistake: you know the material but run out of time. Recommendation: first pass — answer only what you know straight away, mark the hard ones, come back at the end. Don’t spend more than 2 minutes on any single question. Before the exam, run 5 mocks at full pace — that is the main source of confidence.