Thank you for your reply. Yes, I thought I needed to read some books about this thing. I already requested some from my local library. I hope Chapelle is good. I thought of R/C, it is a lot easier. I am now thinking of a yacht deisgn I should make plans of, it turns out I need only a receiver, small batery, and one servo, and a transmitter. That is very cheap compared to airplanes, where you need 5-12 servos, ESC, a motor, strong battery and a reliable receiver..... And all that has to lift itself up into the air. Mine did lift themselves up, still it is much harder than just figuring out the bouyancy of the boat!!!! Can you please tell me how to configure the sails of the yacht so it succesfully maneuvers without any engine? (My books didn't come yet)..
Thank you a lot,
Demosthenes.
P.S. Do you have any pictures of your boats that you could show to me here?