Human-powered hydrofoil

A human-powered hydrofoil is a small hydrofoil watercraft propelled entirely by the muscle power of its operator(s).^[1] Hydrofoils are the fastest water-based vehicles propelled solely by human power. They can reach speeds of up to 34 km/h (21 mph; 18 kn),^[1][2][3] easily exceeding the world records set by competitive rowing which stand at about 20 km/h (12 mph; 11 kn). This speed advantage is achieved since hydrofoils lack a submerged body to provide buoyancy, greatly reducing the drag force.^[1]

Starting an AquaSkipper on the river Spree in Berlin

The Decavitator

An AquaSkipper underway

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]

Electric assist hydrofoils

• The Hydrofoiler XE-1 is a Hydrofoil electric bike developed in New Zealand in 2011 onwards.^[14]