Windsurf · Funboard revolution
1984
The RAF sail rotates around the mast
MauiSails presents the rotating asymmetrical airfoil: battens that swing around the mast, so the sail takes a wing shape on each tack.
RAF
Rotating asymmetrical airfoil, presented by MauiSails in April 1984
A windsurf sail hangs from a round mast that sits right at its leading edge. How to turn that combination into a clean wing was one of the big design questions of the eighties.
MauiSails, the Hawaii sail loft of Barry Spanier and Geoffrey Bourne, presented its answer in April 1984: a new rig concept called RAF, short for rotating asymmetrical airfoil. In an RAF sail the battens and the mast sleeve move around the mast. On each tack the battens swing to the leeward side, and the sail takes an asymmetric wing shape with the mast inside its front.
MauiSails designed sails for Neil Pryde, and the Neil Pryde RAF Wave of 1985 became one of the best-known sails of its time.
The concept had a weakness. When the sailor eased the sail or a strong gust hit, the sail could derotate and let the leading edge cave in. Camber inducers, for which patents were filed the same year, press the battens against the mast for a stiffer profile.