Submarines are usually tight, functional vessels that eschew frills for functionality.

Which is why most submarine passengers are in the navy and not on vacation.

Fortunately, this is not your typical submarine. It's the Under Water Entertainment Platform from Dutch submersibles company U-Boat Worx. And what it lacks in a catchy name, it more than makes up for in luxury and over-the-top possibilities.

The sub can accommodate up to 120 people through its 1,600 square feet of customizable space. It can descend to 200 meters, so you'll always have something to look at through the 14 large porthole windows. And thanks to the abundant power supply, it can stay submerged for up to 18 hours before needing to recharge. There's also a sundeck, so if you go topside, you can take in a sunset or wave to a passing yacht and its wide-eyed passengers.

It's hard to imagine the type of person who'd buy a party submarine. Chances are high they have "Bond villain" printed on their business card. But think of the possibilities...

This sub could be outfitted to become an underwater restaurant, or the world's most exclusive cocktail lounge. It would make for a great casino (international waters and all) or a unique conference location. It could become an extra-tranquil spa, a memorable event space, or perhaps a tour operation, where you say things like, "and on your left, you'll see a confused shark." 

The only limit is your imagination.

And how many zeros you've got in your bank account.