Chart Navigation & Plotting · Aids to Navigation
A buoy showing horizontal bands of red and green with the topmost band green marks a preferred channel and indicates the preferred channel lies to the:
- AStarboard (treat the buoy as a green/port-hand mark — keep it to port)✓ Correct
- BPort (treat the buoy as a red/starboard-hand mark — keep it to starboard)
- CEither side equally
- DBuoy must be passed close aboard
Explanation
A preferred-channel (junction) buoy is colored for the topmost band. Top band green = the buoy is treated as a green can: keep it to port to follow the preferred channel, which lies to starboard of the buoy. Top band red reverses this.
Authority: USCG Navigation Rules; IALA Region B
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