Forces on sails apart, which generally prevents heeling. Each sailing craft is a system that mobilizes wind force through its sails—supported by spars and rigging—which provide motive power and reactive force from the underbody of a sailboat—including the keel, centerboard, rudder or other underwater foils—or the running gear of an ice boat or land craft, which allows it to be kept on a course. Without the ability to mobilize reactive forces in directions different from the wind direction, a craft would simply be adrift before the wind. Accordingly, motive and heeling forces on sailing craft are either "components of" or "reactions to" the
Forces on sails force component (F), is the most significant rotational effect of total aerodynamic force (F). In stasis, heeling moment from the wind and righting moment from the boat's heel force ("F" ) and its opposing hydrodynamic lift force on hull ("F" ), separated by a distance ("h" = "heeling arm"), versus its hydrostatic displacement weight ("W" ) and its opposing buoyancy force ("Δ"), separated by a distance ("b" = "righting arm") are in balance: Sails come in a wide variety of configurations that are designed to match the capabilities of the sailing craft to be powered by them. They are designed