Posted: Mar 04, 2011 7:22 am
by zulumoose
Metatron you have not read the article, basically what he is doing is setting a 'sail' to tack angle and then shifting it backwards and forwards rapidly so that it is tacking to both sides equally. He achieves this by having two rigid and opposing sails rotate, ie a propellor.

It is known fact that a sail can outperform the wind speed, if tacking at an offset angle, so if you do this to both sides with great efficiency you can easily go faster downwind than actual wind speed. All he has achieved is to 'trick' the setup with a propellor design such that he can tack while keeping the hull pointed steadily downwind.