1The mark in plain words
In one sentence…
A cardinal mark shows where navigable water lies: the named quadrant tells you where to pass.
What does it tell you?
It says that navigable water lies on the named side of the mark: North, East, South or West.
What do I check first?
Look for two black cones and horizontal black and yellow bands; the topmark guides identification.
How do I read the light?
North flashes quick or very quick continuously; East gives 3, South 6 plus 1 long, and West 9, and the rhythm separates quadrants.
How do I use it?
Name the quadrant, check bands, cones and light rhythm, because the clues work together before you decide where to pass.
2See it in 3D
Turn the mark to inspect its colours, shape and topmark, then switch to night to see its light.
An interactive 3D illustration is shown here. The same content is described in the rule text and key takeaways below.
3How you recognise it
- North · white (if fitted)
- Black over yellow, black cones up, Q/VQ
- East · white (if fitted)
- Black-yellow-black, black cones base-base, VQ(3) 5s/Q(3) 10s
- South · white (if fitted)
- Yellow over black, black cones down, VQ(6)+LFl10s/Q(6)+LFl15s
- West · white (if fitted)
- Yellow-black-yellow, black cones point-point, VQ(9) 10s/Q(9) 15s
- Long flash
- At least 2 s
- Q / VQ rates
- Q: 50/60, VQ: 100/120
4Key points
- 1.
Navigable water lies on the side named by the mark.
- 2.
North: cones up, black over yellow, continuous Q or VQ.
- 3.
East: bases together, black-yellow-black; South: cones down, yellow over black.
- 4.
West: points together, yellow-black-yellow and 9 quick flashes.
5Frequent mistakes
Wrong: "East and West have the same light rhythm."
Right: East uses 3 flashes; West uses 9.
Wrong: "The mark shows where the danger is."
Right: It identifies the named side where navigable water lies.
Wrong: "The black cones may touch or look joined."
Right: Keep the two black cones clearly separated.
6Exam keys & interpretation
Exam keys
Cones up + black over yellow + continuous Q or VQ = North.
Bases together + 3 flashes = East; points together + 9 = West.
Cones down + 6 flashes and one long = South; the long flash lasts at least 2 s.
How to read it
Read the name as a direction: it tells you the side where navigable water lies.
To decide, combine the three visible clues: bands, cones and light rhythm.
7Full lesson & sources
Open the full lesson (diagrams and official references)
Cardinal marks indicate that the navigable water lies on the named side of the mark. They use black and yellow horizontal bands and two black cone topmarks.
North Cardinal: pass to the north. Topmark: two cones pointing UP. Colours: black above yellow. Light: continuous quick or very quick flashing.
East Cardinal: pass to the east. Topmark: two cones base to base. Colours: black-yellow-black. Light: 3 quick flashes (3 o'clock).
South Cardinal: pass to the south. Topmark: two cones pointing DOWN. Colours: yellow above black. Light: 6 quick flashes + 1 long flash (6 o'clock).
West Cardinal: pass to the west. Topmark: two cones point to point. Colours: yellow-black-yellow. Light: 9 quick flashes (9 o'clock).
White lights, when fitted: North Q or VQ; East VQ(3) 5 s or Q(3) 10 s; South VQ(6)+LFl 10 s or Q(6)+LFl 15 s; West VQ(9) 10 s or Q(9) 15 s. The long flash lasts at least 2 s.
Keep the two black cones clearly separated. Q is 50 or 60 flashes per minute; VQ is 100 or 120.
8Test your knowledge
What does a cardinal mark indicate?
Keep studying…
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