Wetwing

 

Some Remarks from the Inventor Jochen Ewert:

 

Hi,

I would like to mention that my longest flight with the Wet Wing was 20km without touching the water (1hr 55min, Lake Starnberg in Bavaria from south end to north end).

My longest trip was 30km in 3hrs 15min including a 15min break (staying on the boat but floating, not flying).

Regards,

Jochen Ewert

 

 

Hi all who are interested in buying or building another Wet Wing,

this is Jochen Ewert again.

I am afraid that I have to disappoint you, but Wet Wing is a prototype built by me and there is only one unit, which I want to keep for myself.
Also, I never found the time to create plans of it and it would be very difficult for some parts.
At least, here is some info how the different parts of the boat are made:

Framework: Aluminum tubes, carbon fibre tubes, steel cables (very simple, very light, very stiff; I consider it as a good design). Handle bar is standard bicycle part.

Floats: Fibre reinforced polyurethane (as used for life vests in commercial aircraft; needs experience to work with; work not carried out by me but by someone in northern Germany who made them in his garage according to my sketch. I consider it as a good but extreme design: 0.7 kg per float including fixings! Volume 90 liters each.)

Seat: Styrofoam shaped by hand, coated with glass fibre reinforced plastics (epoxy). The shape is optimized for my body. The strength of the seat is optimized for my weight and muscle power (both rather low). Good ergonomics: A 10mm layer of soft foam is enough to stay hours on the boat without pain. Potential for improvement: lighter foam or honeycomb, carbon fibre instead of glass fibre.

Strut (that is the surface piercing part that connects the framework with the wing): Aluminum skeleton, styrofoam coated with glass fibre reinforced plastics. Big potential for improvement: integral carbon fibre (CRP) design, much slender shape.

Wing: Carved cedar wood covered with CRP. Big potential for improvement (weight and performance): integral CRP, greater aspect ratio.

Front foil: CRP, laminated in CNC milled mould. Expensive; good design.

Front strut and surface follower: original parts from Trampofoil (see link on this website)

Drive train: Bicycle serial parts (pedals, cranks, bottom bracket), custom made chain ring (chain pitch 6mm: very light and smooth running), custom made drive train in the strut (second chain, also 6mm chain, Moebius band twisted design).

Propeller: CRP laminated in mould by Theo Schmid of Switzerland (as long ago as 1980's). Seems to be very efficient.

Some general remarks:

The boat has to be designed to your weight and power output. A "one-size-fits-all" design for a human powered hydrofoil is far below optimum. It would work but it's less fun.

If you want to use the boat for long distance rides (10 - 20km), the weight of the boat and your weight are crucial. If the weight is high, you need high power output. In my case, boat plus rider, life vest and filled drinking bottle weigh 75 kg (!).

Regards,

Jochen Ewert