What does WIG stand for in terms of watercraft?

WIG stands for "Wing in Ground effect," which refers to a type of watercraft that utilizes aerodynamic lift generated by wings when they are in close proximity to the water's surface. This phenomenon occurs because the wing's lift is enhanced by the surface of the water, reducing drag and allowing for efficient flight at low altitudes. WIG vehicles can take off and land like boats, but they fly just above the water's surface, which makes them unique. They are designed to exploit the ground effect to achieve higher speeds and energy efficiency during operation.

The other options provided do not correctly represent the WIG terminology used in the context of watercraft design and operation.