You are steaming southward along the west coast of the United States when you sight a buoy showing a flashing green light. How should you pass this buoy?

Correct Answer: Option C — Leave it to your starboard.

Under the IALA-B system used in the United States, green buoys are kept to the starboard side when proceeding from seaward. Steaming southward along the US West Coast is considered proceeding from seaward; therefore, a flashing green buoy must be left to the starboard side of the vessel.