Buoys & Marks
IALA lateral, cardinal, and special marks — colour, shape, topmark and light characteristics.
Two Global Buoyage Systems: IALA A & IALA B
Europe, Africa, India, Australasia and most of Asia.
Port hand: Red
Starboard hand: Green
The Americas, Japan, South Korea and the Philippines.
Port hand: Green
Starboard hand: Red
Key difference: Lateral mark colours (port/starboard) are reversed between regions. Cardinal marks (N/S/E/W), special marks, isolated danger and safe water marks are identical in both systems.
Port Hand (IALA A)
Colour: Red
Shape: Can / Flat top
Topmark: Single red can
Light: Red: Fl(2), Oc, etc.
Keep to port when entering from seaward
Starboard Hand (IALA A)
Colour: Green
Shape: Conical
Topmark: Single green cone (point up)
Light: Green: Fl, Oc, etc.
Keep to starboard when entering from seaward
Port Hand (IALA B)
Colour: Green
Shape: Can / Flat top
Topmark: Single green can
Light: Green
IALA B (Americas/Japan) — reversed laterals
Starboard Hand (IALA B)
Colour: Red
Shape: Conical
Topmark: Single red cone (point up)
Light: Red
IALA B — keep to starboard entering from sea
North Cardinal
Colour: Black over Yellow
Shape: Pillar or Spar
Topmark: Two black cones, points UP
Light: White: VQ(F) or Q(F)
Safe water to the NORTH — pass to the north
East Cardinal
Colour: Black/Yellow/Black (3 bands)
Shape: Pillar or Spar
Topmark: Two black cones, base to base ◇
Light: White: VQ(3) every 5s or Q(3) every 10s
Safe water to the EAST — pass to the east
South Cardinal
Colour: Yellow over Black
Shape: Pillar or Spar
Topmark: Two black cones, points DOWN
Light: White: VQ(6)+LFl every 10s or Q(6)+LFl every 15s
Safe water to the SOUTH — pass to the south
West Cardinal
Colour: Yellow/Black/Yellow (3 bands)
Shape: Pillar or Spar
Topmark: Two black cones, point to point ⌛
Light: White: VQ(9) every 10s or Q(9) every 15s
Safe water to the WEST — pass to the west
Isolated Danger
Colour: Black with Red band(s)
Shape: Pillar or Spar
Topmark: Two black spheres
Light: White: Fl(2)
Isolated danger with navigable water all around
Safe Water / Mid-Channel
Colour: Red & White vertical stripes
Shape: Spherical / Pillar / Spar
Topmark: Single red sphere
Light: White: Iso, Oc, LFl 10s or Morse A
Safe water / fairway — may be passed on either side
Special Mark
Colour: Yellow
Shape: Any shape not conflicting
Topmark: Single yellow X
Light: Yellow
Marks a special area or feature (spoil ground, military, TSS, etc.)
Emergency Wreck Marking
Colour: Blue & Yellow vertical stripes
Shape: Pillar or Spar
Topmark: Standing yellow cross
Light: Blue/Yellow alternating Fl every 1s
Marks a new dangerous wreck
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