BOTH INTERNATIONAL & INLAND You are on watch and sight a vessel showing a high intensity all-round flashing red light. What does this light indicate?

Correct Answer: Option D — a WIG craft when taking off and landing

Rule 23(b) stipulates that a WIG craft must exhibit a high-intensity all-round flashing red light when taking off, landing, or in flight near the surface. This signal is essential for safety, as WIG craft operate at high speeds and have limited maneuverability compared to conventional displacement vessels.