BOTH INTERNATIONAL & INLAND You are on watch and sight a vessel showing a high intensity all-round flashing red light. Which vessel is required to have this light?

Correct Answer: Option D — a WIG craft in flight near the surface

Rule 23(b) mandates that a Wing-in-Ground (WIG) craft, when taking off, landing, and in flight near the surface, shall exhibit a high-intensity all-round flashing red light. This unique signal warns other vessels of the craft's high speed and limited ability to maneuver during these critical flight phases.