A rule of thumb for the average millionaire lottery winner should take note of when buying a super yacht: it will generally cost you 10% of the purchase price to keep it afloat and maintained - each year! Talk about a hole in the ocean in which you throw money. Only the wealthiest can afford some of these glistening sea mansions in this Top 10 list. But think of the benefits of sea air for your health, plus the Mediterranean style meals your galley of chefs will produce for you at any time day or night. A sailing we will go!