BOTH INTERNATIONAL & INLAND Which signal may at some time be exhibited by a vessel trawling?

Correct Answer: Option D — All of the above

Rule 26(b) requires a vessel engaged in trawling to display two all-round lights in a vertical line, green over white, or a shape consisting of two cones apexes together. The options listed are variations or combinations of lights used to indicate specific operational statuses for fishing vessels under the COLREGS.