Propulsion
Means of propulsion include screw propellers, as in hydrocycles; aircraft propellers, as in the Decavitator; paddles, as in a Flyak; oars, as in the Yale hydrofoil sculling project;[4] and flapping wings, as detailed below.
Flapping wing propulsion
Flapping wing propulsion devices are hydrofoils that produce propulsion by forcing a foil to move up and down in the water. The forward motion of the foil then generates lift as in other hydrofoils. A common design consists of a large foil at the stern that is used both for propulsion and keeping the passenger above the water, connected to a smaller foil at the bow used for steering and longitudinal stability. Riders operate the vehicle by bouncing up and down on a small platform at the stern, whilst holding onto a steering column.[5][6] It is started and landed from the shore, or preferably from a dock, and requires a bit of experience. When moving too slowly, it will sink, and the range of possible speeds is 9–30 km/h (5.6–18.6 mph; 4.9–16.2 kn).[6]
Several variations on the design have been developed:
- The Wasserläufer was a forerunner of the design developed in Germany during the 1950s.[7]
- The Flying Fish was developed by Allan Abbott and Alec Brooks in 1984.[8]
- The Pogofoil, with pontoons for flotation, was developed in the US in 1989.[9]
- The Trampofoil was developed in Sweden in 1998.[10]
- The AquaSkipper was developed the US in 2003.[11][12]
- The Pumpabike was developed in South Africa in 2004.[6][13]
