Ekranoplans, also wing-in-ground (WIG) effect crafts
Flying ships pioneered for military purposes in the 1930s by Russian aeronautical engineers. WIG craft flies just above sea level. Their lift is generated by an air cushion created by the ground effect, described as “an increase of lift-to-drag ratio of a lifting system at small relative distances from an underlying surface”
A WIG craft uses the same surface cushion effect as a hovercraft, but instead of an engine and fan to give lift, forward speed and large wings are used to force air under the craft. This creates a dynamic cushion, which lifts the craft clear of the surface.