The most unusual, extravagant ways tech executives like Larry Ellison and Elon Musk have spent their money

Many CEOs make expensive home and land purchases, but perhaps none more so than Oracle founder Larry Ellison. In 2012, the billionaire purchased 98% of the Hawaiian island Lanai.

Ellison reportedly paid $300 million for the island in 2012. It contains 90,000 acres of land and several resorts, and is home to more than 3,200 residents. Ellison plans to use to land to test environmentally friendly practices like solar power and electric vehicles.

Source: Forbes

Unsurprisingly, Tesla and SpaceX CEO Elon Musk has an interest in unusual vehicles. In 2013, for example, he bought the Lotus Esprit submarine car that's used in the James Bond movie "The Spy Who Loved Me." Musk paid $920,000 at auction.

"It was amazing as a little kid in South Africa to watch James Bond in 'The Spy Who Loved Me' drive his Lotus Esprit off a pier, press a button and have it transform into a submarine underwater," Musk said in a statement to Jalopnik at the time. "I was disappointed to learn that it can't actually transform. What I'm going to do is upgrade it with a Tesla electric powertrain and try to make it transform for real."

Source: Jalopnik

Amazon CEO Jeff Bezos has invested $42 million in a mechanical clock that's buried inside a mountain in Texas.

The 10,000-year-clock, as it's called, was created by a group called The Long Now Foundation. It's a 500-foot-tall clock that's powered by thermal cycles and is designed to keep time for millennia.

Source: Business Insider

Bezos has a passion for space, as evidenced by his Blue Origin rocket company. In 2013, the exec also funded an expedition to retrieve the remains of multiple Apollo engines from the bottom of the ocean.

Bezos led a team that sent unmanned robots 14,000 feet down to the bottom of the Atlantic Ocean off of Cape Canaveral, Florida, to gather the engine parts from the Apollo 12 moon mission.

"To bring those pieces up on deck and actually touch them, that brought back for me all those feelings I had when I was 5 years old and watched those missions go to the moon," Bezos said in a video about the expedition, according to the Seattle Times. "If this results in one young explorer, one young adventurer, one young inventor, doing something amazing that helps the world, I'm totally fulfilled."

Source: Seattle Times

Google cofounder Sergey Brin has reportedly invested between $100 and $150 million of his own money in building a 600-foot flying airship.

Brin is said to be building the airship, which would be the world's largest aircraft, out of a NASA research center near Mountain View, California.

He reportedly envisions using it to make deliveries for humanitarian missions or as an "air yacht" for friends and family.

Source: The Guardian

Brin's fellow Google cofounder Larry Page is also interested in flying vehicles, though of a slightly different variety: Page funds three different flying car startups.

Page has invested in a two-seater flying taxi called Cora and a flying boat called Flyer, which are both made by electric flight transportation company Kitty Hawk. He's also involved in Opener, a startup that makes a flying vehicle called BlackFly.

It's not clear how much money Page has invested in these projects.

Source: The Verge

And while many high-powered executives have private planes, Page and Brin one-upped the typical Gulfstream jet. In 2005, they bought a former passenger plane, a Boeing 767-200.

But in true Google fashion, Page and Brin tricked out the inside, adding a dining area, two staterooms with adjacent bathrooms, and multiple seating areas. The jet can hold up to 50 passengers and includes several first-class seats.

Meanwhile, Oracle's Larry Ellison owns a decommissioned Soviet jet fighter, the Mikoyan MiG-29.

Source: The Wall Street Journal