Passive foil power usage

i am developing a passive hydrofoil withou motor.
i simulated it for 3 m/s and came that it produces 30N drag. That leads to 100Watt Power to maintain that speed.
Now compare that speed to the 7kW motors youre using.
I am trying to say that our designs are highly inefficient.

100W… There’s an issue with that calculation somewhere…

Anton,
3m per second seems to be on the low side…
6 to 9 might be more accurate.
Also, in your simulation, what kind of lift are you getting?

To be fair when I designed my first prototype, i was convinced you can foil in the couple 100 watt range after seeing a video of a guy on a foil pulled by a bicycle on the dock or by someone running pulling a rope.
I kind of got the same feeling when kite foiling by unhooking my kite and trying to feel how much pull from the kite I needed to get going… roughly 2 to 3 x 1.5L water bottles.

so yes, there’s some gap between What we need in theory and the power actually coming out of the battery…

Note that even if we use motors capable of up to 7Kw, we usually don’t go that high…
wet out-runner are flying in the 1600 w range and i think dry in-runner with gearbox are in the 1000w range.
The problem is usually taking off where you have to bring the board to a plane first before flying… that’s why the power overhead is needed.