Abstract: The invention is a self-propelled floating decoy for simulating the swimming characteristics of waterfowl. Propulsion in the water is produced by a sculling tail fin (25) which also causes a side to side rocking motion that simulates the back and head movement of a live duck paddling its feet. The decoy includes a flat base (11) with a shallow draft. The flat bottom of the base (10) is the lowest point in the water with no obstructions that would become entangled in congested water. An opening (11c)in the rear end extends through the base (11) so that an electric motor(16) driven propulsion system moves a tail fin (25) coupled to said propulsion system through the opening (11c). A decoy shell (9) representative of a water fowl is attached to the base (11). The tail fin (25) moves from side to side providing a motion to the decoy approximating the motion of a swimming water fowl.