Question 155Navigation General

70% to pass

In the North Sea area, you sight a buoy showing a quick white light with 6 flashes, followed by one long flash at 15 second intervals. Which of the four topmarks shown in illustration D030NG below would be fitted to this buoy?

Diagram for USCG Navigation General: In the North Sea area, you sight a buoy showing a quick white light with 6...
A A
B B
C C
D D
AI Explanation

The correct answer is A. The key characteristic of this buoy is the quick white light with 6 flashes followed by one long flash at 15 second intervals. This pattern corresponds to the Fairway Buoy, which according to the IALA Buoyage System is marked with a topmark of two black cones point-to-point (option A). The other topmark options B, C, and D do not match the buoy's light characteristics, and would be used to mark different types of buoys in the IALA system, such as port-hand, starboard-hand, or isolated danger markers.

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Official Resources
USCG Navigation Rules (COLREGS) 33 CFR Navigation Rules USCG National Maritime Center
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