Lateral marks are navigation aids used in waterways such as harbors, rivers, and channels to guide vessels in staying within the navigable channel and avoiding hazards. These marks indicate the edges of the navigable channel and help mariners determine the direction of safe water travel.
Lateral marks are typically categorized as either “port” or “starboard” marks, based on their position relative to the direction of travel. Port lateral marks are usually colored red and are cylindrical in shape, while starboard lateral marks are usually colored green and are conical in shape. The shapes and colors of lateral marks help to distinguish them from other navigational aids, such as buoys and beacons.
The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) has established a standardized system for the use of lateral marks, known as the IALA Maritime Buoyage System. This system is used by most countries around the world and helps ensure consistency and safety in maritime navigation.
Practical Use of Lateral Marks – Explained
As per IALA Buoyage system, Lateral marks, used in conjunction with a “conventional direction of buoyage”, generally employed for well defined channels. These marks indicate the port and starboard sides of the route to be followed. Where a channel divides, a modified lateral mark may be used to indicate the preferred route. Lateral buoys indicate the side on which they may be safely passed.
Definition of ‘Conventional direction of buoyage’
The ‘conventional direction of buoyage’, which must be indicated in appropriate nautical charts and documents, may be either:
The general direction taken by the mariner when approaching a harbour, river, estuary or other waterway from seaward.
The direction determined by the proper authority in consultation, where appropriate, with neighbouring countries. In principle, it should follow a clockwise direction around land
Description of Lateral Marks used in – Region A
Lateral Port Hand marks.
- A port hand buoy marks the port (left) side of a channel or the location of a danger which must be kept on the vessel’s port (left) side when proceeding in the upstream direction.
- A port hand buoy is coloured Red , displays identification letter(s) and odd number(s)
Lateral Starboard Hand mark.
- A starboard hand buoy marks the starboard (right) side of a channel or the location of a danger which must be kept on the vessel’s starboard (right) side when proceeding in the upstream direction.
- A starboard hand buoy is coloured Green , displays identification letters and even numbers.
Modified lateral marks in Region A.
At the point where a channel divides, when proceeding in the “conventional direction of buoyage,” a preferred channel may be indicated by a modified Port or Starboard lateral.
Description of Lateral Marks used in Region B.
Lateral Port Hand marks.
- A port hand buoy marks the port (left) side of a channel or the location of a danger which must be kept on the vessel’s port (left) side when proceeding in the upstream direction.
- A port hand buoy is coloured Green , displays identification letter(s) and odd number(s)
Lateral Starboard Hand mark.
- A starboard hand buoy marks the starboard (right) side of a channel or the location of a danger which must be kept on the vessel’s starboard (right) side when proceeding in the upstream direction.
- A starboard hand buoy is coloured Red , displays identification letter(s) and even number(s) .
Modified lateral marks in Region B.
At the point where a channel divides, when proceeding in the “conventional direction of buoyage,” a preferred channel may be indicated by a modified Port or Starboard lateral.
Lateral Marks Poster in PDF Download
Cardinal marks easy Reference poster
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