A type of windsurfing sails without camber inducers. Usually shortened as RAF sails.
RAF sails have battens which protrude ahead the back aspect of the mast. They have to flip to the other side of the mast when tacking or jibing, hence the rotation in the name. RAF sails have aerofoil shape on the leeward side only when filled with the wind. They can be absolutely flat and depowered when sheeted out. This feature is much appreciated in the freestyle and wave riding disciplines.
In comparison with cambered sails, RAF designs offer less power and stability when sailing straight, but are easier to handle when manoeuvering. Also, RAF sails are much easier to rig.