Developing the prototype/Launch party (1967)
To make the prototype, Jim Drake (the sailor) made the booms, fittings, dagger board, and worked with a sail maker. Hoyle Schweitzer (the surfer) designed and built the board, and located a suitable mast.
Before the Windsurfer's free-sail system, boats were steered by a rudder controlled by the sailor. Jim and Hoyle knew a rudder wasn't going to work on their prototype because the sailor wouldn't be sitting down and wouldn't have a hand free to direct the rudder. The sailor for their prototype would be standing up, and both hands would be supporting the sail. Jim and Hoyle decided to create a way to steer their rudder-less board with the sail.
They knew that to steer with the sail they would need an offset between the center of effort (the sail) and the center of resistance (the centerboard that was in the water). To address this fundamental, they attached a fixed mast (much like a traditional boat mast) directly onto the centerboard. This connection between the mast position and the centerboard allowed the center of resistance (the rake of the centerboard) to shift fore and aft when the center of effort (the sail) was adjusted fore and aft, thus allowing the board to be steered without a rudder. Theoretically this seemed like the answer, so Jim and Hoyle built the prototype, and Jim took it out for a test sail before the launch party.
The prototype didn't work, but everyone recalled it was a good party.
The problem with the first prototype was that the mast was fixed to the board, and it was difficult to get on and begin sailing. So, when the sail was down, the board was on its side. And when the board was flat, the sail was standing. Basically, there was no "starting" or "stopping" position. As Jim recounted the challenges of his test run at the launch party, the solution seemed obvious to many, the sail needed to be free to fall in all directions. Hoyle remembers that Allen Parducci speculated, "why not use a rope to connect the rig to the board?"