Millionaires and billionaires have long enjoyed the pleasures of their private jets and luxury yachts. The latest plaything to surge in popularity among the super rich is the private submarine.

Graham Hawkes, the inventor of one of the latest slimline, sporty submarines, told Der Spiegel "We're building the Learjets of the deep" as he spoke with pride of the Deepfleet Super Falcon model. Only the mega rich should think of owning one of Hawkes's lightweight subs as they come with a super high price tag. Richard Branson recently purchased one of Hawkes' Merlin submarines which he rents out for $25,000 a week at his private island, Necker. According to Born Rich there are estimated to be 100 luxury submarines at a cost of $25 million, though Hawkes's company, Hawkes Ocean Technology, has developed models around the $1 million mark and intends to make the price tag more accessible at $250,000. Subs can vary considerably in size, ranging from the latest two seater's to 5,000 square-foot luxury liners. Microsoft's Paul Allen opted for a $12 million yellow submarine, an absolute bargain compared to U.S. Submarines Phoenix 1000 model, with a jaw dropping price of $80 million for the submersible yacht.