This guide covers the main buoy types you’ll encounter, following the IALA Maritime Buoyage System (Region A) — which is used in Europe, including around Mallorca.
1. Lateral Marks
These indicate the edges of a channel.
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Port-hand mark Colour: Red
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Shape: Can (cylindrical)
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Topmark: Red cylinder
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Light (if lit): Red light — any rhythm except those used for cardinal, isolated danger, or safe water marks (often Fl R 5s).
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Meaning: Keep this buoy to your port (left) side when entering from seaward.
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Starboard-hand mark Colour: Green
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Shape: Conical
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Topmark: Green cone (point up)
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Light (if lit): Green light — any rhythm except those reserved for other marks (often Fl G 5s).
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Meaning: Keep this buoy to your starboard (right) side when entering from seaward.
2. Cardinal Marks
These indicate the direction of safest water relative to a hazard.
Named for the cardinal points (North, East, South, West).
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North Cardinal Colour: Black above yellow
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Topmark: Two black cones pointing up
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Light: Continuous quick (Q) or very quick (VQ) white flashing
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Meaning: Safe water lies north of the mark.
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East Cardinal Colour: Black with yellow band in middle
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Topmark: Two black cones, points apart (like an hourglass)
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Light: Q (3) or VQ (3) every 10 seconds
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Meaning: Safe water lies east of the mark.
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South Cardinal Colour: Yellow above black
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Topmark: Two black cones pointing down
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Light: Q (6) + long flash (LFl) every 15 seconds, or VQ (6) + LFl 15s
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Meaning: Safe water lies south of the mark.
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West Cardinal Colour: Yellow with black band in middle
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Topmark: Two black cones points together (point up & point down)
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Light: Q (9) or VQ (9) every 15 seconds
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Meaning: Safe water lies west of the mark.
3. Isolated Danger Mark
Marks a small, isolated danger with safe water all around.
- Colour: Black with one or more broad horizontal red bands
- Topmark: Two black spheres
- Light: Group flashing white (Fl (2)) every 5 or 10 seconds
- Meaning: Danger lies immediately beneath or nearby; keep well clear.
4. Safe Water Mark
Indicates there is navigable water all around.
Often used to mark the start of a channel.
- Colour: Red and white vertical stripes
- Shape: Spherical, pillar, or spar
- Topmark: Single red sphere
- Light: White, usually Iso 10s, Oc 10s, or LFl 10s (may also be Morse “A”: one short, one long)
- Meaning: Safe water in all directions.
5. Special Mark
Indicates special areas or features (not primarily for navigation safety). Examples: traffic separation zones, mooring areas, military exercise zones, or regatta areas.
- Colour: Yellow
- Topmark: Yellow “X” (St. Andrew’s cross)
- Light: Yellow light — any rhythm not used for white lights on cardinal/safe water/isolated danger marks
- Meaning: Check your chart or sailing instructions for specific meaning in the area.
6. Emergency Wreck Marking Buoy
Introduced to mark new wrecks until a permanent mark can be placed.
- Colour: Blue and yellow vertical stripes
- Topmark: Yellow cross
- Light: Alternating blue and yellow flashing (1s each)
- Meaning: Marks a recently sunk wreck; avoid area.
Quick Light Rhythm Reference Table
Originally published on the Mallorca Sailing Academy Journal. Share your thoughts, questions, and experiences below!