A Personal Submarine
When yachting gets to be too boring and scuba diving takes too much effort, it’s time to buy a personal submarine. For the low price of $5.5 million, you could own the Triton 660, a one-man sub that’s supposedly the “world’s deepest diving acrylic hulled submarine” and comes with a reserve 96-hour air tank. Well, you can’t. But a billionaire could.