Forget super yachts, try a super-SUB: Luxury $2.35 million submarine comes with leather seating and a Bluetooth stereo | Super Yacht Sub 3 can carry three people to a depth of 984 feet (300m) | The submersible is designed as an accessory for luxury super yachts | With a top speed of 2.8 knots (3.2mph), it has a battery life of eight hours [Futuristic Submarines: futuristicnews.co...]