BOTH INTERNATIONAL & INLAND Which light(s) must a sailing vessel of over 20 meters in length while underway exhibit?

Correct Answer: Option A — stern light

Rule 25(a) requires a sailing vessel underway to exhibit sidelights and a stern light. While smaller vessels may combine these into a single lantern, a vessel over 20 meters in length must carry a stern light, which is essential for indicating the vessel's orientation to overtaking traffic.