Hi guys! Found this in youtube:
Could maybe be a nice inspiration for some of you guys 
Cheers
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Good find. Thank you.
how about this:
cordless, waterproof
Technical specs: Battery: 18V Li-ion 3Ah No Load Speed (2 speeds) 0-400 / 0-1500 RPM Maximum Torque: 39N/m Chuck size: 13mm Net weight (with battery): 2.9kg (6.39 pounds) Capacity (steel): 10mm Capacity (wood): 25mm Submersible up to: 50m (164 ft)
https://www.amazon.com/DIVERS-CORDLESS-UNDERWATER-DRILL-Nemo/dp/B013XAM7MM
Anyone have a grand to spare to strap this onto a foil and try it?
Probably not strong enough to get you out of the water but it might work, at 1500 you can use a torqeedo prop. Those are designed for 1400 rpm. If you can feed the battery and extend the throttle. But it might overheat soon.
At 1000 usd you just buy something better I think.