IALA buoyage System
For historical reasons, two different schemes are in use worldwide, differing in their use of colour.
Previously there had been 30 different buoyage systems, prior to IALA introducing the rationalised system. In 1980 on a conference convened by IALA, they agreed to adopt the rules of a new combined system, which combined the previous two systems (A and B) into one system, with two regions (A and B).
The IALA defines them as Region A and Region B:
- Region A comprises nations in Europe, Australia, New Zealand, parts of Africa and most ofAsia other than the Philippines, Japan and Korea.
- Region B comprises nations in North America, Central America and South America, thePhilippines, Japan and Korea.
- port marks are red and may have a red flashing light of any rhythm.
- starboard marks are green and may have a green flashing light of any rhythm.
- port marks are green and may have a green flashing light of any rhythm.
- starboard marks are red and may have a red flashing light of any rhythm.
- port marks are square or have a flat top
- starboard marks are conical (or present a triangular shape) or have a pointed top.
The shape is an important feature, as colours cannot be distinguished in some light conditions, or by persons with red-green colour blindness. Marks may also carry unique markings of letters and numbers; these may be used to identify the mark as one indicated on anautical chart. Likewise, a mark’s light may flash in a distinctive sequence for the same purpose.
Also defined in the lateral mark systems is a bifurcation mark, which has both red and green horizontal bands, one over the other. This mark indicates that a “preferred” channel (often, a deep channel suitable for heavy commercial traffic) lies to one side, and a secondary channel on the other. Vessels wishing to use the preferred channel observe the top colour of the mark, and vessels wishing to use the secondary channel observe the bottom colour.
In Region A only, the phrase “Is there any red port left?” (referring to the red colour of the fortified wine “port”) may be used as a mnemonic, indicating that a red mark must be kept on the left when “returning” to (i.e, entering) a harbour or river.
In Region B only, the phrase “red right returning” may be used as a mnemonic, indicating that a red mark must be kept on the right whenreturning to (i.e., entering) a harbour or river.