I am surprised they put the windkite on the bow, and not on the middle of the ship.
Biceaus when the wind comes a little bit from the side, the kite will pull the bow of the ship to another direction. And then, they most use their rudder to correct that, and that costs a lot of speed.
@firestar 12:
I don't think that when the wind drops, the kite will go 3m underwater and to the center of the ship to get caught in the propellor. I never saw a kite like that sink
And wind on sea can't just drop to nothing when there is enough wind to use the kite.