Sails are the engine of sailboats. Like any engine sails need careful preparation and maintenance to get the performance. This article is aimed to guide you trim your sails in relation to the weather conditions and therefore improve your knowledge about the physics of sailing.
Combination of Forces on Sailboat
However, before we explain the techniques it is good to understand how a sail works and what makes it more efficient the sails act in many ways like an airplane wing. The physics of sailing similar airplane wings which is designed to maximize lift and minimize drag.
How does the sail work?
When the air flows over the sail the air flowing over the curve travels a longer distance than the air on the other side. So wind can produce low pressure at the curved side than the other side. The sailboat moves into the low-pressure zone and is pulled forward (force on sails). The keel, a large almost flat area under the sailboat, has to push a lot of water sideways. The water resists this, and produce a force on the keel. The combination of these forces creates propulsion and determines the speed and direction of the sailboat. This is the physics of sailing.