Red, Left, Return – What? Understanding the Two Buoyage Systems

I was recently in Auckland, New Zealand, and noticed a couple of buoys in the harbor that reminded me of home. (For those who don’t know me, I’m English.) In this photo, the boat docks are to the left, and the open ocean is to the right.

Many of you are considering exciting international sailing vacations to the Mediterranean, Adriatic, Asia, and Australasia, so I thought it was worth reminding everyone that the world uses two different buoyage systems — and most of these destinations follow a different one than the U.S.

IALA A vs. IALA B: What’s the Difference?

The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) defines two buoyage systems:

• IALA System B: Used by the Americas (Canada to Argentina, including the Caribbean), Japan, Korea, and the Philippines.

• IALA System A: Used by the rest of the world — including Europe, Australia, New Zealand, and much of Asia.

In the U.S. (IALA B): Red Right Returning

In IALA B, we use the easy-to-remember phrase: Red Right Returning — keep the red buoys on your right (starboard) side when returning from the open sea. This makes it easy to remember.

• Red buoys: Triangular, numbered evenly

• Green buoys: Square, numbered oddly

In Europe, Australia & More (IALA A): Red on the Left

In IALA A, it's the opposite:

• Red buoys: Kept to the left, square, and odd-numbered

• Green buoys: Triangular, even-numbered

So if you’re chartering a yacht in Greece, Croatia, or Thailand, remember — Red Left Returning applies instead.

Did the U.S. Change Buoy Colors to Confuse the British?

One story suggests that U.S. buoys were “swapped” during the Civil War to confuse British ships. While it makes for a good tale, it’s likely the buoys were simply repainted, not rearranged, the shapes and numbering stayed the same.

It’s much easier to visualize:

Why This Matters: Safety First

Before the global agreement in 1982, over 70 different buoyage systems were used worldwide. On April 15th, 1982, representatives from 53 nations met in Paris to standardize the IALA Maritime Buoyage System, greatly improving maritime safety.

This system is known as a "lateral buoyage system" — meaning buoys mark the sides of navigable channels, not the middle. You won’t find runways of lights like an airport — it’s up to you to know which side to pass on, and in which direction.

Quick Buoyage System Recap

Region	System	Red Buoys	Green Buoys
Americas (IALA B)	Red Right Returning	Right, Triangle, Even	Left, Square, Odd
Rest of World (IALA A)	Red Left Returning	Left, Square, Odd	Right, Triangle, Even

Understand Your Buoys and Stay Safe

Sailing internationally is exciting, but navigation rules can change with the hemisphere. Whether you're sailing in the U.S. or abroad, understanding buoy systems is essential for safety.

Planning a Charter? Get Certified First

If you're looking to charter a yacht in international waters, make sure you have the correct credentials.

For info on obtaining your internationally recognized sailing certification, accepted by all charter companies, click here.