Photos

Peter Chilvers as a 12 year old English boy on Hayling Island on the south coast of England, was the first person to produce a board with a sail. This board formed the basis for modern windsurfers.
The history of windsurfing, and its ultimate inventor are a source of much conjecture in the windsurfing community. Some courts have recognised Chilvers' testimony as proof of prior art. His testimony led to a successful legal defense in 1980,83,85. See Windsurfing International Inc. v Tabur Marine (GB) Ltd. 1985 RPC 59. This case set a very significant precedent in Patent law in terms of Inventive step and non-obviousness. No photo or plans of a 1960 era Chilvers sailboard were produced for the courts.
Invention of windsurfing has also been attributed to 3 other inventors. Newman Darby is often incorrectly credited as the first man to conceive the idea of connecting a hand-held sail rig fastened with a universal joint to a floating platform for recreational use, in the early sixties. He published his design in August 1965 Popular Science magazine. Darby had organized Darby Industries, Inc. in 1964 to build what they called sailboards. However, Darby's boards were inefficient and did not enjoy significant popularity [1].
Jim Drake, a Californian aeronautical engineer and his friend Hoyle Schweitzer with his wife Diane Schweitzer commercially developed the windsurfer and made it commercially successful. Drake had designed a surfboard-like board with a triangular sail and wishbone booms, connected to the board via a universal joint, and Schweizter popularized the new sport. The details of the original designs are available in Drake's whitepaper on windsurfing. Also, the history of invention is discussed in this interview with Jim Drake. Drake recognizes he re-invented what Chilvers and Darby have conceived earlier.
Drake and Schweitzer patented the invention in 1968. Schweitzer incorporated Windsurfing International for promoting the sport and managing the patent, and bought the rights from Drake in 1973.
Windsurfing caught on in Europe, and local companies started manufacturing windsurfing equipment. In 1983 Schweitzer sued a Swiss board manufacturer Mistral for infringing on his patent, however Mistral won the case by bringing up prior art by Darby. Schweitzer had to reapply for a patent under severely limited terms, and finally it expired in 1987.
Windsurfing experienced a boom in the 1980s. Windsurfing became an Olympic sport in 1984. However, windsurfing popularity saw a sharp decline in the mid-1990s, as equipment became more specialized, requiring more expertise to sail. Now the sport is experiencing a modest revival, as new beginner-friendly designs are again becoming more readily available.

From Wikipedia