Can't stop looking at this. These things are practically flying. Yet turning on a dime.
The AC72 (America's Cup 72 class) is a wing sail catamaran box rule, governing the construction and operation of the yachts to be used in the 2013 Louis Vuitton Cup selection series and the 2013 America's Cup. This new and revolutionary design is extremely expensive and has allowed the development of foils that lift the hull out of the water, in some conditions leading to extreme boat speeds well over 40 knots (74 km/h; 46 mph).
It was expected to sail faster than the wind: upwind at 1.2 times the speed of the true wind, and downwind at 1.6 times the speed of the true wind. But in fact it proved faster, averaging about 1.8 times the speed of the wind with peaks slightly over 2.3. Emirates Team New Zealand sailed at 44.15 knots (81 km/h, 50 mph) in 15.8 knots of wind (2.79 times the wind speed) on July 18, 2013.