09/06/2026
🌐🌐Understanding Marine Buoy Colors and Types in IALA Regions A and B
Safe navigation relies on a standardized system of marine aids to navigation. The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) defines two buoyage regions: Region A and Region B.
A common misconception is that all buoy colors change between the two regions. In reality, only lateral marks (port-hand and starboard-hand marks) differ between Region A and Region B. All other navigation marks—including cardinal marks, isolated danger marks, safe water marks, emergency wreck marking buoys, and special marks—are identical worldwide.
Understanding this distinction is essential for mariners operating internationally.
⚠️Lateral Marks: The Only Marks That Change Between Regions
Lateral marks indicate the edges of a navigable channel and guide vessels when entering a harbor, river, or channel from seaward.
🔸IALA Region A
Used throughout Europe, Africa, most of Asia, Australia, and New Zealand.
Port-hand mark: Red color, can-shaped topmark when fitted.
Starboard-hand mark: Green color, cone-shaped topmark when fitted.
🔸IALA Region B
Used in North America, Central America, South America, Japan, South Korea, and the Philippines.
Port-hand mark: Green color, can-shaped topmark when fitted.
Starboard-hand mark: Red color, cone-shaped topmark when fitted.
The shape of the marks remains the same in both regions. Only the colors are reversed.
A useful reminder for Region B is the phrase "Red Right Returning", meaning that a vessel returning from sea keeps the red marks on its starboard side.