This may sound like a rich person’s problem, but it is probably challenging to find a place to dock your superyacht in Miami. Yet Mark Cuban, the businessman who owns the Dallas Mavericks and is a regular investor on the TV program “Shark Tank,” luckily found an open spot on the Miami River Canal for his 288 foot ship called the Fountainhead. Cuban probably compares notes with Larry Ellison. The billionaire co-founder of Oracle owns the sister ship named Musashi. These yachts rank among the top 50 largest in the world.