When must a WIG craft keep well clear of all other vessels?

A WIG (Wing-in-Ground) craft must keep well clear of all other vessels during takeoff and landing due to the specific operational characteristics of this type of vessel. During these phases, the craft operates in close proximity to the water's surface, relying on ground effect for lift. This makes it particularly vulnerable to collisions, as its maneuverability may be limited, and it may not respond as predictably as other types of vessels. Maintaining a safe distance from other vessels during takeoff and landing ensures the safety of not only the WIG craft but also other nearby vessels and their crews.

Other scenarios, such as being moored at a dock or only during bad weather, do not impose the same immediate risk of collision, and powered-off status does not inherently reduce the danger from nearby vessels. Thus, the critical safety measure is in effect during the more dynamic and potentially hazardous phases of flight—the takeoff and landing.