Foot operated propulsion system for watercraft

1. A device adapted to be inserted in a watercraft comprising propulsion means extending below the water line carried by a support member, said propulsion means comprising a pair of flexible flappers each adapted to oscillate through an arcuate path in a generally transverse plane with respect to a central longitudinal dimension of said watercraft, one flexible flapper rotating in one direction and the other flexible flapper in the opposite direction, and means operatively associated with said propulsion means for applying input force to said propulsion means whereby as input force is applied, said flexible flappers can twist to form an angle of attack for providing forward thrust with respect to the longitudinal dimension of the watercraft while moving in both directions along said arcuate path, wherein said means for applying input force comprises a pair of pedals coupled to said flexible flappers such that as one pedal moves down the other pedal moves up, the fore ends of the pedals being pivotally attached so as to pivot about an immovable essentially horizontal axis essentially perpendicular to the center line of the watercraft and the aft ends of said pedals being free to pivot about said axis whereby an operator can apply step-wise force on the pedals.

2. A device adapted to be inserted in a watercraft comprising propulsion means extending below the water line carried by a support member, said propulsion means comprising a pair of flexible flappers each adapted to oscillate through an arcuate path in a generally transverse plane with respect to a central longitudinal dimension of said watercraft, and means operatively associated with said propulsion means for applying input force to said propulsion means whereby as input force is applied, said flexible flappers can twist to form an angle of attack for providing forward thrust with respect to the longitudinal dimension of the watercraft while moving in both directions along said arcuate path, wherein said means for applying input force comprises a pair of pedals, and further including pedal cranks operatively associated with said propulsion means, the fore ends of the pedals being pivotally attached about a fixed point on an upper surface of a watercraft and the aft ends of said pedals being free to make rolling or sliding contact with said pedal cranks whereby an operator can apply force to the pedal cranks by applying step-wise force on the pedals.

3. A device adapted to be inserted in a watercraft, said device comprising propulsion means extending below the water line carried by a support member, said propulsion means comprising a pair of flexible flappers each adapted to oscillate through an arcuate path in a generally transverse plane with respect to a central longitudinal dimension of said watercraft, and means operatively associated with said propulsion means for applying input force to said propulsion means whereby as input force is applied, said flexible flappers can twist to form an angle of attack for providing forward thrust with respect to the longitudinal dimension of the watercraft while moving in both directions along said arcuate path, wherein said means for applying input force comprises a pair of pedals, and further including pedal cranks operatively associated with said propulsion means, the fore ends of the pedals being pivotally affixed to an upper surface of said watercraft and the aft ends of said pedals being free to make rolling or sliding contact with said pedal cranks whereby an operator can apply force to the pedal cranks by applying step-wise force on the pedals.

4. A novel watercraft having propulsion means extending below the water line carried by an immovable support member, said propulsion means comprising a pair of flexible flappers each adapted to oscillate through an arcuate path in a generally transverse plane with respect to a central longitudinal dimension of said watercraft, and means operatively associated with said propulsion means for applying input force to said propulsion means whereby as input force is applied said flexible flappers can twist to form an angle of attack for providing forward thrust with respect to the longitudinal dimension of the watercraft while moving in both directions along said arcuate path wherein said means for applying propulsive force comprises a pair of pedals, and further including pedal cranks operatively associated with said propulsion means, the fore ends of the pedals being pivotally affixed to said immovable support member and the aft ends of said pedals being free to make rolling or sliding contact with said pedal cranks whereby an operator can apply force to the pedal cranks by applying step-wise force on the pedals.

5. The watercraft of claim 4 wherein the watercraft is a paddle board.

6. The paddle board of claim 5 where a stationary upright is provided fore of the operator for grasping while pedaling.

7. The paddle board of claim 5 wherein a seat is provided aft of the operator.

8. The watercraft of claim 4 wherein the watercraft is a small boat.

9. The small boat of claim 8 wherein a stationary upright is provided fore of the operator for grasping while pedaling.

10. The small boat of claim 8 wherein a seat is provided aft of the operator, the seat being substantially above the upper extremity of the hull of the boat.

11. The watercraft of claim 4 wherein the watercraft is a kayak.

12. The kayak of claim 11 wherein a stationary upright is provided fore of the operator for grasping while pedaling.

13. The kayak of claim 11 wherein a seat is provided aft of the operator, the seat being substantially above the upper extremity of the hull of the kayak.