Yacht ownership has always been a beloved hobby of the well to do. But the recent phenomenon of the mega-yacht — sometimes called the superyacht — has taken it to a whole new level.

With prices ranging from $200 million to a incredible $1.1 billion, the megayacht is the plaything of the world's wealthiest individuals. So just who are these people?

They come from all different places and made their money in a variety of ways — there are Hollywood tycoons and oil Sheikhs, politicians and industrialists. But they all have one thing in common. They are all billionaires.

Here are the 15 most expensive mega yachts in the world and the billionaires who own them.