The vehicle is NOT pedal-propelled!
This is the official press release:
Nereus is a conceptual design of a water craft, that allows to achieve relatively high speeds on water and under water. The user can change between swimming and diving as he wishes. Wind energy should be used to propel the vehicle in the form of a power kite.

The control element is pivot-mounted, so it can be aligned according to the Kite’s position. The upper body is quite involved in this and is used to counter balance the pull. The control element provides controls to operate the kite, including a DePower handle. Submerging is also initiated using the control element. Emersion works without any user input, by taking advantage of the shape of the fins and the resulting ascending force.
Steering of the vehicle itself is controlled using the footrests, that are linked to the rudder at the back.

Similar to other kite sports, sailing against the wind is possible by heading in a zigzag way towards LUV.

Thanks for clearing the concept out Jacques... The lack of actual wind sails in the design sketches really puzzled me out too...

Could you perhaps change ”pedal-propelled” to ”kite-driven” in the head line? Everything should be clear then.

That’ the editors’ prerogative... I hope the correction is satisfactory... also if you could clear out how the kite is still stuck to the craft when the craft goes underwater, and whether thats a hinderance in its functioning underwater, it wud be perfect for our readers!!

There’s another image on my website, that hopefully explains all obscurities: http://www.optisch-edel.de/images/nereus6.jpg

The lines of the kite don’t add any resistance and the kite itself stays on top of the water all the time. Submerging happens only shortly below the surface and for short periods of time.