Module 16 - Pilotage
Cardinal Marks
What you will learn
Identify each cardinal mark from topmark, bands or white light rhythm and state the named side of safer water with a chart-checked margin.
A cardinal mark indicates the compass side on which safer water lies relative to a point of interest. Its two cones, black-and-yellow bands and quick or very quick white rhythm provide independent checks.
North has both cone points up and black over yellow; south has both points down and yellow over black. East has points apart with bases together and black-yellow-black bands; west has points together and yellow-black-yellow. State the message with the name: north cardinal—safer water lies north of the mark.
At night, north shows uninterrupted quick or very quick white flashes. East shows Q(3) every 10 seconds or VQ(3) every 5 seconds; west shows Q(9) every 15 seconds or VQ(9) every 10 seconds; south shows six quick or very quick flashes followed by one long flash. The long flash prevents south being confused with a nine-flash group.
The named side is the initial message, not an instruction to pass close. Consult the chart to see what feature is being marked and choose a route using depth, tide, traffic and turning room. If a topmark is missing or the rhythm cannot be counted reliably, hold off and use the other cues.
Use topmark, band order and rhythm as separate confirmation cues.
| Mark | Topmark | Body colours | White light if lit | Safer side |
|---|---|---|---|---|
| North | Both points up | Black over yellow | Q or VQ continuous | North |
| East | Points apart | Black-yellow-black | Q(3) or VQ(3) | East |
| South | Both points down | Yellow over black | Q(6)+LFl or VQ(6)+LFl | South |
| West | Points together | Yellow-black-yellow | Q(9) or VQ(9) | West |
Turn nine flashes into a route decision
A white light shows groups of nine quick flashes near a charted rocky shoal. The body is not yet visible.
1. Identify
A group of nine quick or very quick flashes identifies a west cardinal mark.
2. State the message
Safer water lies west of the mark relative to the charted feature.
3. Plan the margin
Use the chart, depth, tide and traffic to choose a track west with sensible clearance.
Sense check: Recognition is incomplete until 'west cardinal' becomes 'safer water west' and a chart-checked passing plan.
Common mistake or limitation
- A north cardinal does not say the danger is north; it says the safer water lies north of the mark.
- South is six quick or very quick flashes plus a long flash—the long flash is part of the identity.
Recap
- Say the safer side every time you name a cardinal mark.
- Cross-check cone direction, black-band position and white rhythm.
- Use the chart to understand the feature and choose a conservative margin.
Optional quick check
Section 7 of 12
A mark shows yellow-black-yellow bands and two cone points together. What is the safe-water message?
Sources and factual review
Reviewed 2 September 2026 - Compass Revision editorial review.
Continue studying Pilotage
This public lesson is part of Revision Module 16. Full revision access adds the guided Learn, Practise and Test flow, flashcards and revision progress.