In the North Sea area, you sight a buoy showing a quick white light with 9 flashes every 15 seconds. Which of the four topmarks shown in illustration D031NG below would be fitted to the buoy?

Correct Answer: Option A — A

A light characteristic of 9 flashes every 15 seconds identifies a West Cardinal mark in the IALA system. The corresponding topmark for a West Cardinal buoy consists of two cones pointing toward each other, apex to apex, which is represented by illustration A.