International buoyage conventions are determined in many countries by the IALA (International Association of Marine Aids to Navigation and Lighthouse Authorities) system.

The IALA system contains two regional divisions (A and B), each of which has a slightly different buoyage system. Region A covers areas in Europe, Africa, Australia and most of Asia, whilst region B applies in North and South America, Japan and the Philippines.

The system sets out 5 different types of navigation marks - Lateral, Cardinal, Isolated Danger, Safe Water and Special marks, which are used alongside other types of navigation aids such as Lighthouses, Lightbuoys, and Sectored, Leading and Moiré lights.

Use the link to the left to find out more about each type of mark.