You sight a spar buoy with the top mark shown in illustration D027NG below. You must take which of the following actions?

Correct Answer: Option D — keep well clear of the buoy and pass on either side

The topmark shown (two cones pointing away from each other) identifies an Isolated Danger Mark. These marks are placed directly over a danger of limited extent and have navigable water all around them. Therefore, you should keep well clear of the buoy and may pass on either side of it.