Question 329Navigation General

The correct answer is B) a single red sphere. The IALA Buoyage System (Region A) specifies that the topmark of a red and white vertically-striped buoy shall be a single red sphere. This is to visually identify the buoy as a cardinal buoy, which marks the direction in which mariners should navigate to pass safely. The other answer choices are incorrect because: A) two black spheres is the topmark for a port-hand lateral buoy, C) a single red cone is the topmark for a starboard-hand lateral buoy, and D) an X-shaped topmark is used for a special-purpose buoy, not a cardinal buoy.