IALA Buoyage System — Region A
The IALA (International Association of Marine Aids to Navigation and Lighthouse Authorities) system provides a standardised set of buoys and marks used worldwide. The UK and most of Europe use Region A (the Americas use Region B, which reverses port/starboard colours).
There are five types of marks: Lateral marks (port and starboard channel edges), Cardinal marks (indicating where safe water lies relative to a hazard), Isolated Danger marks, Safe Water marks, and Special marks.
Key Points
- Region A used in UK, Europe, most of world (Region B = Americas)
- Five types: Lateral, Cardinal, Isolated Danger, Safe Water, Special
- All marks have specific colours, shapes, top marks, and light characteristics