Question 136Navigation General

70% to pass

In the North Sea area, you sight a buoy showing a quick white light showing 6 flashes followed by one long flash at 15 second intervals. Which of the four topmarks in illustration D031NG 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 showing 6...
A A
B B
C C
D D
AI Explanation

The correct answer is C. The characteristics of the light described (quick white light showing 6 flashes followed by one long flash at 15 second intervals) indicate that this is a composite group flashing white light, which is associated with a special purpose buoy according to the IALA Buoyage System. The topmark shown in option C, consisting of two black spheres, is the standard topmark used to identify a special purpose buoy. The other options do not match the characteristics of the light described, and would not be the appropriate topmark for this type of buoy.

Ready to test your knowledge?

Take a Navigation General Practice Exam

Want to practice with timed exams?

Download Coast Guard Exams for the full exam experience.

Get the App