Buoyage

Buoyage is the international system of marking waterways with buoys, beacons, and fixed structures. Not to be confused with buoyancy (a vessel’s ability to float), the term encompasses all IALA Maritime Buoyage System rules. Two regions exist: IALA A (Europe, Africa, most of Asia, Australia) and IALA B (Americas, Japan, Philippines). The principal difference lies in lateral mark colours. In IALA A, when entering a port from the sea, green cone-shaped buoys (with a triangular topmark) are kept to starboard and red cylindrical buoys to port; IALA B reverses this.

Apart from lateral marks, the system includes cardinal marks (showing the safe side relative to a hazard), safe water marks (indicating deep water all around), isolated danger marks, and special marks (spoil grounds, bathing areas, cables). Each mark may carry a light of a specific colour and rhythm. Exact positions and characteristics are published in nautical almanacs and electronic charts. A reliable magnetic bearing, taken with a marine compass, helps confirm mark identity. For a broader exploration of navigation skills, visit our Navigation tag. Mastering buoyage is essential for skippers to safely navigate narrow channels and avoid grounding.