The unconventional wing-sail vessel Vestas Sailrocket has claimed the record for fastest speed under sail, with an average of 47.35 knots over 500 meters, pending ratification by the WSSRC.
From www.sailrocket.com:
“The boat was smoking… but balanced. I held onto it until I was certain that a solid 500 meter average was recorded… and then dumped the flap and eased the wing. No more big bear aways to slow down. I pulled on the leading edge bridle to slow her down by feathering the wing and it worked a treat. Hiskia caught the boat on the shore. I was pretty surprised by the data on the GPS. It read a top speed of 48.90 knots and an average of 47.35! I told the team over the VHF that they were now looking at the fastest boat in the world….”
Video from a practice run: