The Hydroptère is an experimental sailing hydrofoil designed by French yachtsman Alain Thébault. Her multihull hydrofoil design allows the sail-powered vessel to reach high speeds on water. The design is based on experience from a range of hydrofoil sailcraft that Thébault built in cooperation with the late Éric Tabarly since the 1990s. On October 5, 2008 she reached a record speed of 52.86 knots (97.90 km/h; 60.83 mph), however this was over a shorter distance than the 500m necessary to qualify for an official world record On December 21, 2008, the Hydroptère briefly reached 56.3 knots (104.3 km/h; 64.8 mph) near Fos-sur-Mer, but capsized shortly thereafter.
On September 4, 2009, the Hydroptère broke the outright world record, sustaining a speed of 52.86 knots (97.90 km/h; 60.83 mph) for 500m in 30 knots of wind. In November 2009, she broke the 50 knot barrier for a nautical mile with a speed of 50.17 knots (92.91 km/h; 57.73 mph) in Hyères, France.