sailboat

sailboat move with the wind through the sails i guess...

You need to get a bit technical!! Yes the sail acts like an aeroplane wing - the flow of air is faster on one side than the other and this creates a pressure difference giving a force at right angles to the sail. This force can be be considered to be a composed of two forces at right-angles to each other. Pity I can't show diagram. One force acts in the direction of the boat whilst the other force is at right-angles to the boat. The First Force drives the boat forward. The Second Force is cancelled out (mostly) by the resistance of the hull, keel or centreboard - the boat will move slightly sideways with an effect called 'leeway'. If the wind is 45 degrees to the boat then the boat will move along that line ie at 45 deg.to the wind. When you have considered it has gone far enough, then the direction of the boat is changed through 90 deg.(wind 45 deg.on the other side) to go in the other direction. This is called 'tacking' and so a zig-zag course is made good against the wind.

I have no idea. I think it just involves a lot of physics I had learnt a long time back.

The air moving across the sail acts in a similar manner to that of an airplane, it creates lift that pushes the boat forward, with tacking and rudder control you are then able to move across the body of water.

ya.. i think it is the air.. :)