You're probably not rich enough for this luxury submarine

If you're both extremely wealthy and also have a love of the deep blue sea, there's plenty of options already available for you to splurge on. You can drop some pretty serious coin on any number of luxurious yachts -- from big names like Bugatti, among others -- and watch millions of dollars vanish before your eyes. But if you're simply bored of the idea of being ostentatious above the waves, perhaps you'd like to take your extravagant lifestyle below the surface in a 12-person luxury submarine ...