The Importance of Buoyage
Attempts to establish an international uniform system of buoyage have never met with success. A system proposed in 1936 under the auspices of the League of Nations might have succeeded had not World War II intervened before a sufficient number of maritime States had ratified the system. The buoyage system adopted for British waters was based on the 1936 proposals. The system called the ‘lateral system’ is based on knowledge of the direction of the main stream of flood. The sides of channels are marked by buoys described as ‘starboard hand’ or ‘port hand’, these terms denoting the side that would be on a mariner’s right-hand or left-hand, respectively, when going with the main flood stream or approaching a harbour from seaward.
Types of Buoys
Starboard-hand buoys are conical in shape; painted black or in black-and-white chequers; a top mark (if fitted) of a black cone or a black diamond; and a light (if one is carried) of one, three or five white flashes.
Port-hand buoys are can-shaped; painted red or in red-and-white chequers; a top mark (if fitted) or a red can or red T; and a light (if one is carried) of two, four or six white flashes.
Middle-ground buoys, which mark the ends of middle grounds, are spherical in shape. The lights they may exhibit are either white or red and distinctive, so that there is no uncertainty as to which side they must be passed. In cases in which the main channel lies to starboard (when proceeding with the main flood stream), or when channels are of equal importance, middle-ground buoys are painted with red-and-white horizontal bands.
In cases in which the main channel lies to port (when proceeding with the main flood stream) they are painted with black-and-white horizontal bands. When top marks are carried, if the main channel lies to starboard (when proceeding in the direction of the main flood stream) the outer end middle-ground buoy is marked with a red can and the inner end with a red T. If the main channel lies to port, the outer end top mark of a middle-ground buoy is a black cone and the inner end a black diamond. If the channels are of equal importance, the outer and inner end buoys are marked with a red sphere and a red St. George’s Cross, respectively.
Mid-channel buoys are painted with black-and-white or red-and-white vertical stripes, Buoys marking isolated dangers are spherical and are painted with wide black-and-red horizontal bands, separated with a narrow white band. Landfall buoys, serving to indicate the seaward approach to a harbour exhibit flashing lights and are painted with black-and-white or red-and-white vertical stripes.
Buoys marking wrecks in the lateral system are painted green with the word WRECK in white letters. They exhibit green flashes: one flash to indicate that the buoy (spherical in shape) may be passed on either hand; two flashes to indicate that the buoy (can-shaped) is to be passed on the starboard hand; and three flashes to indicate that the buoy (conical) is to be passed on the port hand.
As well as the lateral system described above, the 1936 proposed buoyage scheme included a ‘cardinal system’ designed for use on coasts fringed with reefs or isolated dangers. The buoys in this system have shape lights, colours and top marks which indicate whether the buoy is to be passed to the north, East, South or West. The 1936 scheme allowed the lateral and cardinal systems to be used in conjunction, but special conical buoys painted with black-and-white or red-and-white diagonal stripes, mark the places where a change in the system occurs.
There are many systems of buoyage, besides those described above, in current use, and the mariner should be perfectly aware of the details of every system he encounters, from a careful study of the relevant sailing directions.
In 1977, the buoyage in the southern North Sea was completely changed to conform with a system devised by the International Association of Lighthouse Authorities (IALA). The intention is that the IALA system will be extended to embrace all the waters of North-West Europe. Navigators need to be familiar with this system (and indeed every other system encountered) so that they react instinctively when using the buoyage system.
The essential feature of the ‘IALA Maritime Buoyage System A’ is red for port-hand and green for starboard-hand buoys. The ‘lateral’ buoys, which indicate the port and starboard hands of well-defined channels, are painted red for port-hand buoys and green for starboard-hand buoys. A port-hand is can-shaped and has a can as a top mark and a starboard-hand buoy is conical in shape and has a cone as a top mark.
By night a port-hand buoy is distinguished by its red light and a starboard-hand buoy by its green light.
A buoy used to indicate the direction of deeper water relative to it is called a ‘cardinal buoy’. Such buoys are pillar or spar buoys in combinations of black and yellow colours, with black double-cone top marks. A North cardinal buoy is one that should be passed to the north of the buoy, is painted black above yellow and has a top mark consisting of two black cones, both pointing upwards. A South cardinal buoy is painted yellow above black and has a top mark consisting of two black cones both pointing downwards. An East cardinal buoy is painted black with a single broad yellow band and has a top mark of two black cones base to base. A West cardinal buoy is painted yellow with a single broad black band and has a top mark consisting of two black cones point to point.
A cardinal buoy exhibits a white light, the characteristics of which are based on a group of very quick or quick flashes, which distinguishes it first as a cardinal mark and then indicates its quadrant. The distinguishing flashes are:
North Cardinal: uninterrupted flashes
East Cardinal: 3 Flashes in a group
South Cardinal: 6 flashes in a group
West Cardinal: 9 Flashes in a group.