Windsurf · Funboard revolution
1984
Camber inducers give the sail a fixed wing profile
Jeffrey Magnan's design for Gaastra couples the battens to the mast, so a race sail keeps its aerofoil shape instead of flapping into it.
US 4,686,921, Figs. 4–6 (1987): top view at the mast, the rig, the camber inducer · public domain
A soft sail takes its shape from the wind, and it changes shape as the wind changes. Racers wanted the opposite: a sail that holds a deep, fixed aerofoil like a wing. The answer was the camber inducer.
On 28 March 1984 Jeffrey J. Magnan filed a patent, assigned to the sailmaker Gaastra, for what he called a flex wing apparatus. The battens of the sail are coupled to the mast through pivoting fittings, so that the sail and battens can swing around the mast when tacking, the camber can be set with the outhaul, and the airflow over the mast stays smooth. The United States patent was granted in 1987; an international application with the same priority date was filed as well.
Camber inducers became a feature of racing sails. In windsurfing literature the inventor’s name is sometimes spelled Magnum, but the patents all read Magnan.