For fun – it’s Friday! – I thought compile a list of the world’s coolest waterborne vehicles. Some are appropriate for scuba diving or general recreation; others are geared towards research; but all of them are ingenious and ultra-cool.

* The SeaOrbiter is a 150-foot tall, 30-foot wide research lab intended to study life beneath the waves. The SeaOrbiter’s cost is estimated to be $50 million. Checking out SeaOrbiter’s specs will tell you why. 

* The Jelly-Fish 45 is a floating mansion 33 feet tall and 45 feet wide. Appointed with teak flooring and powered by photovoltaic panels, the $2.5 million Jelly-fish is a high-end houseboat with a submerged lower deck for dining, drinking, and enjoying the view. 

* SportSub manufactures 2, 3, and 6-person submarines, for personal, resort, or "surveillance" use. Prices start at $44,000. SportSubs are depth-rated to 130 feet.  

* The Solar-powered Autonomous Underwater Vehicle allows for long-term exploration of the sea and lakes. The SAUV can dive to 1500 feet. 

* BOB is a DIY ROV that uses $20 bilge pumps as thrusters and eBay’ed vintage Atari joysticks as controllers. BOB cost around $500. 

* The Surf Shark is a 2-foot-tall battery-powered thruster contained within a fiberglass body. Held betwen the legs, one passenger controls the Surf Shark, which costs $3300, and can operate it on the surface or to a depth of 30 feet. 

* The Trilobis 65 is a circular, four-leveled vessel, connected by a spiral staircase. The lowest level of the Trilobis is a submerged observation deck roomy enough for 6. 

* The Exosuit is an ultra-lightweight “hardsuit” that can take a diver to depths of 600 feet. Dr. Phil Nuytten developed the Exosuit. 

* Seahorse Submarines manufacture 1-, 2-, 3-, 5- and 7-seater recreational subs. Seahorses can dive to 140 feet. 

*Finally, the Amphibidiver is a car that can drive to the water, drive into the water, submerge, anchor while you dive, ascend, and drive home. The Amphibidiver may be the coolest vehicle on the planet. 

If this list didn’t satisfy you, try Land, Air, and Sea for a few other unique amphibious vehicles.