BOTH INTERNATIONAL & INLAND Which of the following describes a vessel exhibiting the lights shown in illustration D056RR below?

Correct Answer: Option D — dredging while underway

Rule 27(d) requires a vessel engaged in dredging or underwater operations to display three all-round lights in a vertical line, the highest and lowest being red and the middle white, indicating the side of obstruction and the side on which it is safe for another vessel to pass.