Abstract: A rigid or inflatable water craft propelled by a double-flipper device for safe displacement both for the user and nearby swimmer.consists of a floater specifically linked to a propelling system comprising a pedal mechanism with discoid branches with protected pedals actuating two cog wheels secured to two rods connected by pivot pins and sliding in two tubes at the end of which are fixed aquatic flippers. The rotation of the cog wheels, acting as a reduction gear box, about the axles fixing them to the outer hull open in its rear part enables to obtain effortlessly a constant and continuous flapping movement of the flippers in a common vertical plane, such as that produced by a human and known to be most efficient. The device is particularly designed for the general public for use in an aquatic environment in the form of nautical activities for leisure, sport or exercise.

Abstract: The invention concerns a rigid or inflatable water craft propelled by a double-flipper device for safe displacement both for the user and nearby swimmers. It consists of a floater specifically linked to a propelling system comprising a pedal mechanism with discoid branches (1) with protected pedals (2) actuating two cog wheels (3) secured to two rods (5) connected by pivot pins (4) and sliding in two tubes (6) at the end of which are fixed aquatic flippers (8). The rotation of the cog wheels, acting as a reduction gear box, about the axles (9; 10) fixing them to the outer hull open in its rear part (11) enables to obtain effortlessly a constant and continuous flapping movement of the aquatic flippers in a common vertical plane, such as the one produced by a human and known to be the most efficient. The inventive device is particularly designed for the general public for use in an aquatic environment in the form of nautical activities for leisure, sport or exercise.