Nun buoy is red in color and marked with what number parity?

• A. An odd number
• B. An even number
• C. No number
• D. A prime number

Answer: (B)

In the IALA buoyage system, the color and shape of a buoy tell you which side of the channel you’re on, and the numbers follow a parity pattern. Red conical buoys are called Nuns and mark the port (left) side of the channel when coming from the sea. They are numbered with even numbers. The green cylindrical buoys, called Cans, mark the starboard (right) side and carry odd numbers. So a red Nun buoy is identified by an even-numbered mark. This parity rule helps you quickly confirm your position relative to the channel as you navigate.