Buoyage is the "highway code" of the sea. Knowing buoys and marks is essential to navigate safely. Here are the key visual diagrams for your studies.
Buoyage regions A and B
The world is divided into two main regions for the lateral buoyage system (port and starboard sides):
- ARegion A (rest of the world) Europe, Africa, Australia and most of Asia. Here, RED is port and GREEN is starboard (when entering port).
- BRegion B (the Americas and nearby) North, Central and South America, Japan, Korea and the Philippines. The colours are REVERSED compared with Region A.
Note: Spain belongs to Region A.
Shapes of the marks
Colour is not all that matters: the shape of the buoy or its topmark tells you what it is, even against the light or if you cannot tell colours apart well (colour blindness and boat licences).
Cylindrical
Port lateral mark (Region A)
Conical
Starboard lateral mark (Region A)
Spherical
Safe water
Cross (X)
Special marks
Cardinal marks
They show the safe side to pass (north, south, east or west). They are black and yellow. The key is in the little triangles (cones) on top:
- ▲▲ NORTH Points up. Black on top.
- ▼▼ SOUTH Points down. Black at the bottom.
- ▼▲ EAST Base to base (egg shape). Black at top and bottom.
- ▲▼ WEST Point to point (hourglass, wasp waist). Black in the middle.
The "clock" of the lights
To identify cardinal marks at night, think of a clock face. The number of flashes matches the hour:
EAST (3 o’clock)
3 quick flashes every 10 s (approx.).
SOUTH (6 o’clock)
6 flashes + 1 long flash. (The long flash avoids confusion with 3 or 9.)
WEST (9 o’clock)
9 quick flashes every 15 s.
NORTH (12 o’clock)
Continuous quick (Q) or very quick (VQ) flashing. It never stops.
New danger
It marks a newly discovered danger (wreck, obstruction) that is not yet shown on nautical charts.
Key features:
- Vertical blue and yellow stripes.
- Topmark: yellow cross (vertical + horizontal, a '+' sign).
- Light: alternating blue and yellow (1 s blue, 0.5 s dark, 1 s yellow, 0.5 s dark).
What about ship lights rather than buoy lights? That is COLREG: what COLREG is and who has right of way, with an encounter simulator to try it, and ships’ navigation lights, one by one.