No. Hovercraft use a cushion of air trapped under the vehicle and allowed to bleed out under the skirts to hold the vessel off the water and reduce the friction against the water's surface so they can be moved fairly effieciently.
The Ground Effect Vehicles are indeed flying and generating lift aerodynamically by the movement of their wings through the air. But by flying just a few feet off the water the greatly reduced drag from ground effect enables them to fly with far less energy expended than if the same machine were to fly at altitude.
So they can fly fairly fast--- some 300 miles an hour in the case of the Soviet machines-- and carry a good size load. The power that would otherwise be needed to provide a lot of lift at altitude can instead be used to provide less lift but carry a heavier load in ground effect.
If you talk to one of your local cormorants or pelicans he or she will be able to give you a much better explanation of ground effect and its benefits than I can. In the photo below I am getting a detailed explanation and demonstration of ground effect from the cormorant I went fishing with on the Li River in China the other year.
When my videographer took this shot the cormorant was getting quite frustrated with my inability to grasp nuances of the air's movement around his wings in ground effect and how he could alter it almost infinitely by moving his trailing edge and wingtip feathers. So he was in the middle of giving me a graphic demonstration of his feather-activation system when Tom took the shot.