In a normal sail car you'd have to tack, but otherwise the same forces apply. The clever thing about the propellor is you get a sort of cork-screw-tacking for f

In a normal sail car you'd have to tack, but otherwise the same forces apply. The clever thing about the propellor is you get a sort of cork-screw-tacking for free allowing your motion to be in-line with the wind instead of having to be at an angle.