Your diagram is very good! Also the two force diagrams at the bottom are illuminating. Maybe you could add the lateral force of the water acting on the keel/hull/dagger board balancing the large lateral component of the sail force, which is essential for the whole argument (without it the hot-air baloon argument would be correct). In addition I much agree with your first sentence.
falling cat
editI got a very big grin out of File:Cat fall 150x300 6fps.gif. Besides illustrating the physics well, that is a darn cute little kitty (simple 3D rendering and all). Nicely done. —Steve Summit (talk) 18:09, 8 December 2014 (UTC)
- Thanks. The full version of that animation is here: https://www.youtube.com/watch?v=yGusK69XVlk
- --Eyytee (talk) 21:42, 21 December 2014 (UTC)