Sail tips.

Just found this info sheet on a web site, thought id share it with you all as it contains a good bit of information and is also easy to read and understand.

Work with nature and try to pick wind shifts. Real sail trimming control like true yachts!

At first glance, sailing a yacht doesn't look so simple. The first mistake is thinking that by filling the sail, the wind will provide the pushing power to make the yacht travel fast. However a yacht sail actually acts like an aerofoil that pulls the yacht along, while working with the keel in the water to create forward energy. Of course there are cases of running 100% with the wind behind, but usually this will not be the case. The same applies to R/C model yachts as well. Just like a real yacht, the sail servo can trim the sail in and out according to the angle of the wind for the optimum sail shape. Learning how to read the wind is a real skill. Using a force that you can't see makes R/C yachts all the more fascinating.

The pressure created from the air flow across the surface of the filled sail forces the yacht to lean to the right (starboard side) and produces forward energy. The wind causes the hull to lean. However, the keel at the bottom of the hull acts as a countervailing force against the pressure of the wind, and minimizes sideways (leeward) motion of the hull. Forward momentum is generated by wind travelling past the sail.