You sight a spar buoy with the topmark shown in illustration D027NG below. You must take which of the following actions?
Official USCG Answer & Rule Citation
Correct Answer: Option D — keep well clear of the buoy and pass on either side
A topmark featuring two cones pointing away from each other (bases together) designates an isolated danger mark. Per Bowditch and IALA standards, vessels must keep well clear and pass on either side of the obstruction.
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