https://thenextweb.com/syndication/2019/10/06/an-engineer-explains-how-supercharged-racing-yachts-go-so-fast/

Sailing used to be considered as a rather sedate pastime. But in the past few years, the world of yacht racing has been revolutionized by the arrival of hydrofoil-supported catamarans, known as “foilers”. These vessels, more akin to high-performance aircraft than yachts, combine the laws of aerodynamics and hydrodynamics to create vessels capable of speeds of up to 50 knots, which is far faster than the wind propelling them.

An F50 catamaran preparing for the Sail GP series recently even broke this barrier, reaching an incredible speed of 50.22 knots (57.8mph) purely powered by the wind. This was achieved in a wind of just 19.3 knots (22.2mph). F50s are 15-meter-long, 8.8-meter-wide hydrofoil catamarans propelled by rigid sails and capable of such astounding speeds that Sail GP has been called the “Formula One of sailing”. How are these yachts able to go so fast? The answer lies in some simple fluid dynamics.