Bored of making out on a plane at 35,000 feet? Adventurous couples who’ve already inducted themselves into the Mile High Club can now take their love to a new level, with the launch of a luxury submarine that plumbs the depths of the ocean and comes with soundproof rooms and a private chef.The underwater marine hotel called “Lovers Deep” can be moored near the coastal reef off the coast of St. Lucia or near a sunken battleship in the Red Sea. But love at the bottom of the ocean doesn’t come cheap. You’ll need to cough up $292,800 USD, (£175,000) per night in order to board the submarine vessel. Take a look at the luxury submarine hotel launched by British travel outfit Oliver’s Travels as part of their Mile Low Club, and a few other underwater alternatives to banal skyscraping suites.