I have to admit, thats one of the most impressive boats I've seen (designwise). It looked like it was airborn at a little over 6mph (impressive). The automatic electronic control of all the foils is awesome, and the boat appeared to sail nicely with little effort from the crew.
I'm just curious why they located the main foils so far aft, it looks like a pitchpole waiting to happen to me, I guess I'll never know, as my German sucks.
There is a guy named Tom Spears ( http://www.tspeer.com/Hydrofoils/hydrofoils.html
) has quite a bit of experimentation with foils, most of the stuff I did follows his stuff, I used the xfoil program to design mine ( http://web.mit.edu/drela/Public/web/xfoil/
), and used Solidworks to design all the component parts.
For those not interest in designing/building from scratch, you can buy the Tfoils directly from Hydrosail ( I think their about $1000 bucks ea) at ( https://sites.google.com/site/hydrosail/
), they are the same foils used on the Rave.
Here is a video of an Osprey 18 ( http://vimeo.com/35372827
It actually might work to take an old H18 or 21, design new cross rails (to make it much wider), add the foils. The only stock parts would be the hulls and the sail rig system, would be a fun project.