Check out the MIGALOO. It's easily the most one of a kind yacht on the planet! It's not only 375 feet long and 36 feet wide, but it can also function as a submarine! It's got it's own boat dock for smaller craft, a pool and a helipad - all of which can easily retract to allow you to take the entire thing underwater! You know, for when you need to go on a stealth vacation.