On Sept. 4, in the Hyères harbor in the south of France near Marseille, l’Hydroptère became the fastest sailing boat on the planet. Alain Thébault and his crew achieved a speed of 51.36 knots/59.1 mph over a distance of 500m and 48.72 knots/56 mph over one nautical mile (subject to ratification from the World Sailing Speed Record Council or WSSRC) in a 28-knot/32-mph westerly wind.
Fabricated primarily from carbon fiber-reinforced composites with titanium metal in key locations, the sizable 18.3m/60 ft long trimaran boat is engineered for extremely low weight — only 6.5 metric tonnes (14,300 lb). Therefore, at a certain speed, its submerged foils or underwater “wings” can achieve sufficient vertical thrust to lift the hulls above the water’s surface. The foils, then, are the only parts of the vessel in contact with the water, resulting in a very small wetted area and, thus, almost insignificant hydrodynamic drag.
The principle of foils has been known since the 1800s, and many concepts have been advanced over the years, including one by Alexander Graham Bell in 1919. As a concept boat, l’Hydroptère first “flew” in 1994, and has been improved and optimized since. According to Thébault, the stress exerted on the foils is such that “it was necessary to wait for the advent of high-tech materials, such as carbon and titanium, in order to be able to make a large-sized boat fly over the waves.”
The team says that speed records on the open ocean, including long distance records, are the next challenges.