Hmmmmmm!! my imagination is piqued. What can you do with a Mainsail that you can't talk about. it's not a sheep for heaven's sake. Seems somewhat unproductive to take a tall self tending mainsail sail that provides much of the horsepower, especially off the wind, to drive the boat and replace it with a much smaller, shorter self tending sail in the same place. The higher you go off the water, the faster the wnd velocity, up to a point. Taller sails are better for light air work.