Windsurf · One design boom
1978
A patent for lifting a windsurf board on hydrofoils
Two Americans claim clip-on hydrofoils that lift an ordinary windsurf board out of the water, an idea that would take decades to become the norm.
US 4,508,046, Fig. 1 (1985) · public domain
On 10 April 1978 James C. Coulter and Michael P. Shannon applied for a patent on what they called a wind surfing hydrofoil apparatus. Their idea was to fit detachable hydrofoil units to the side edges of a windsurf board, so that as the board picked up speed the foils would carry it and lift the hull out of the water.
The patent claims that 1978 application as its priority; the US filing is dated 8 February 1984 and the patent was granted on 2 April 1985 as US 4,508,046.
Windsurfing at the time was moving in another direction, towards boards with footstraps for strong wind and waves. The principle in this patent, a board flying on underwater wings instead of planing on the surface, is the one that carries Olympic windsurfers on the iQFoil today.