IALA maritime buoyage system

Where in force, the IALA System applies to all fixed and floating marks except lighthouses, sector lights, leading lights and leading marks, light-vessels and lanbys. The standard buoy shapes are cylindrical (can), conical, spherical, pillar and spar. Variations may occur; for example, light-floats. In the illustrations below, only the standard buoy shapes are used. In the case of fixed beacons (lit or unlit), only the shape of the top-mark is of navigational significance.

Lateral Marks are generally for well-defined channels. There are two international Buoyage Regions, A and B, where Lateral marks differ.

IALA Buoyage Regions A and B

A preferred channel buoy may also be a pillar or a spar. All preferred channel marks have horizontal bands of colour. Where for exceptional reasons an Authority considers that a green colour for buoys is not satisfactory, black may be used.
 

Direction of Buoyage The direction of buoyage is that taken when approaching a harbour from seaward or along coasts, the direction determined by buoyage authorities (normally clockwise around land masses).
	Symbol showing direction of buoyage where not obvious.
	Symbol showing direction of buoyage on multicoloured charts.

Small channels may be marked with willow poles called withies.