Abstract: A diver lying prone in the water grasps the invention with his hands and pushes on pedals with his feet. The pedal motion is converted into propulsive force that moves the diver through the water. The diver is free to bend at his hip joints and bend and twist his spine to cause turns, dives and ascents in the water. The preferred embodiment of the propulsion means comprises a simple direct drive of an arm. As the diver operates the pedals the forward end of the arm pivots with respect to the device as the rearward end of the arm sweeps back and forth in the water. A fin is attached to the rearward end of the arm. The fin is fitted with a simple device for controlling the angle of attack of the fin with respect to the flow of water past it.

Abstract: A diver lying prone in the water grasps the invention with his hands and pushes on pedals with his feet. The pedal motion is converted into propulsive force that moves the diver through the water. The diver is free to bend at his hip joints and bend and twist his spine to cause turns, dives and ascents in the water. The preferred embodiment of the propulsion means comprises a simple direct drive of an arm. As the diver operates the pedals the forward end of the arm pivots with respect to the device as the rearward end of the arm sweeps back and forth in the water. A fin is attached to the rearward end of the arm. The fin is fitted with a simple device for controlling the angle of attack of the fin with respect to the flow of water past it.