Submarines Now The Super-Rich's Favorite New Toy (VIDEO)

To check out the new favorite toy of the mega-rich, you'll have to do some deep sea diving.

That's because that new plaything is a single-person submarine designed to venture seven miles underwater to the Challenger Deep -- the deepest place in the ocean.

This week, Titanic and Avatar director James Cameron plans to set a new record at the helm of his submarine by riding solo and spending six hours down under the sea collecting footage for National Geographic, according to Earlier this month, he broke another world depth record by taking the capsule five miles below the ocean's surface to the New Britain Trench, according to the The New York Times .

"It's a blast," Cameron said in an interview with NYT. "There's nothing more fun than getting bolted into this and seeing things that human beings have never seen before. Forget about red carpets and all that glitzy stuff."

His partner in a broader mission to explore the deepest underwater locations is billionaire and Virgin Group founder Richard Branson, who originally unveiled a single-person submarine back in April 2011, according to Bailey S. Barnard, associate editor of Robb Report, a magazine for the ultra-wealthy, said the vessel is becoming so popular that he plans to feature it as part of the magazine's upcoming "Toys of Summer."

Though an underwater submarine may seem a bit extreme, spending money on quirky items isn't anything new for the super rich. Last week, Bloomberg News reported that some ultra wealthy families have emergency rooms worth $1 million in their own homes.