Overmarine Group Shipyard is pretty well known in the marine world, especially because it's the owner of the Mangusta brand, which gives the world some of the largest luxury yachts. The brand considers itself to stand for excellence in luxury and peak performance, offering boats that are easy to use and incredibly quick. The Mangusta 165 is, according to Overmarine, the biggest open yacht in the world at 163 feet long, blowing size and performance expectations out of the water.