BOTH INTERNATIONAL & INLAND What day shape shall a vessel 15 meters in length, proceeding under sail as well as being propelled by machinery, exhibit?

Correct Answer: Option C — a cone with its apex downward

COLREG Rule 25(e) mandates that a vessel proceeding under sail when also being propelled by machinery shall exhibit, where it can best be seen, a conical shape, apex downward. This informs all approaching traffic that the vessel is legally treated as a power-driven vessel.