Hydroptère is an experimental sailing hydrofoiltrimaran designed by French yachtsman Alain Thébault. Its multihullhydrofoil 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 5 October 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 21 December 2008, the Hydroptère briefly reached 56.3 knots (104.3 km/h; 64.8 mph) near Fos-sur-Mer, but capsized and turtled shortly thereafter.
On 4 September 2009, the Hydroptère broke the outright world record, sustaining a speed of 52.86 knots (97.90 km/h; 60.83 mph) for 500 m (1,600 ft) in 30 knots (56 km/h; 35 mph) of wind. In November 2009, she broke the 50-knot (93 km/h; 58 mph) barrier for a nautical mile with a speed of 50.17 knots (92.91 km/h; 57.73 mph) in Hyères, France.
During July 2015, the Hydroptère sailed 2215 nautical miles from Los Angeles to Honolulu and docked in Kewalo Harbor. On March 15, 2016 the Harbor Master posted an "Abandoned Vessel" notice on the Hydroptère which was subsequently sold.