Is it possible to use a hydraulic motor to drive the prop, pumping oil through the foil? It seems like putting a pump at the top and running it at high rpm is far easier at the top of the board, where space is not so much limited.
I’ve never seen a hydraulic motor before and don’t really know if foil can hold up to pressures needed for these motors to run… curios if this idea is too crazy and if anyone looked at that before.
It wouldn’t save much space. Granted it does take the electronics above the waterline, but now your having to deal with another motor/pump in the board.
I thought about it and I personally would like to have my motor in the board. I have no knowledge about hydraulics though.
Interesting idea!
you can definitively get insane amounts of torque to run large props!
but there will be quite a heavy and complex system with hydraulic hoses, pumps, overpressure valves, electric motor, hydraulic fluid tank, batteries, esc++. I am guessing 10kg+ only the hydraulics.
found several pump and motor packs in the 48v,3kw range, but they all look a bit to big. I think it is possible to make a costume motor pump assembly that is “light weight”. Only my thoughts please prove me wrong. 
