The IALA Maritime Buoyage System is an internationally recognized system of buoys, beacons, and navigation marks used to guide vessels safely at sea and in navigable waterways. Developed by the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA), it helps mariners identify safe channels, hazards, isolated dangers, and special areas through standardized colors, shapes, topmarks, and lights. The system includes Lateral Marks, Cardinal Marks, Isolated Danger Marks, Safe Water Marks, Special Marks, and Emergency Wreck Marking Buoys, providing mariners with a common and reliable system for safe navigation worldwide.

An Isolated Danger Mark identifies a localized hazard surrounded by safe, navigable water. It has a black body with one or more red horizontal bands, two black spheres as its topmark, and a white light flashing twice in a group (Fl(2)) when fitted.

A Safe Water Mark indicates navigable water around the mark and may be used to identify the center of a channel, mid-channel, or landfall. It has red and white vertical stripes, a single red sphere as its topmark, and a white light when fitted.

A Special Mark identifies a specific area or feature mentioned in nautical charts or publications, such as pipelines, cables, recreation zones, or special-purpose areas. It is yellow, carries a yellow “X” topmark, and displays a yellow light when fitted.

An Emergency Wreck Marking Buoy is used to temporarily identify a new wreck or newly discovered hazard until permanent marking is established. It has blue and yellow vertical stripes, a yellow upright cross topmark, and an alternating blue and yellow flashing light when fitted.