The 49er is the men's double-handed skiff class in the olympic games. The boat is 4.9m in length and has wings extending the width of the hull to about 2.8m. The wings and the double trapeze means the crew can provide maximum leverage to the massive sail area and achieve speeds of up to 45 km/hour. This extreme and exciting sailboat has been in the Olympics since the 2000 Sydney games. The class attracts the best sailors in the world, many of whom also compete for the America's Cup.
Photo from the London 2012 Olympics