IALA maritime buoyage system

IALA maritime buoyage system, an international system of buoys used globally for navigation. Up to 1976 there were more than 30 different systems worldwide, many having rules which contradicted each other, and the history of attempting to find a universal system is a long one. In 1882 Trinity House, the British authority then responsible for buoys, called a conference of all other national authorities concerned. This eventually took the form of an international marine conference at Washington, DC, in 1889 at which a uniform system was one of the subjects discussed. Most of the maritime nations attended, and the conference recommended the adoption of a lateral, or side-marking, system based partly on shape but primarily on colour. It was agreed that buoys marking the starboard side of a channel, defined as that on the right hand of a ship entering from seaward or going with the main flood tidal stream, should be coloured black and be conical in shape. Those marking the port side should be red or chequered, and can, or truncated cone, in shape. No agreement was reached on the marking of the middle grounds, which in Britain was always done with spherical buoys.

Another international marine conference took place at St Petersburg in 1912 and an attempt was made to reverse the Washington decision, but the proposal was not accepted. But later some countries, particularly those bordering the Baltic Sea, found the lateral system not entirely suitable for their waters, and adopted a new system known as the cardinal, or directional, in which a combination of shape, colour, and topmark was used to indicate the compass quadrant in which the buoy was moored relative to the danger it marked. Countries exclusively using the cardinal system were Norway, Sweden, and Russia; Germany, Italy, and Turkey also used it either in addition to or in combination with the lateral system.

The catalyst for change came when there were a series of disastrous collisions in the Dover Strait in 1971. As a result the International Association of Lighthouse Authorities (IALA) began implementing two new systems, A and B. The rules of these were later combined into what is now known as the ‘IALA maritime buoyage system’ which operates in two regions, A and B. A, comprising Europe, South Africa, Australasia, and some Asian countries, uses red to mark the port-hand side of a channel when entering with the flood tide, and green for the starboard side. Region B, comprising North, Central and South America, Japan, Korea, and the Philippines, uses green to mark the port-hand side and red for the starboard. The system uses five types of marks: lateral, cardinal, isolated danger, safe water, and special. Exact details of the buoyage system in use in any particular country are given in the sailing directions appropriate to those waters.