Highland Systems has a history of creating notable defense vehicles, from an APV to a superyacht. Most look like pipe dreams, yet most have at least had a prototype built. This leads us to the Kronos armored submarine. Nearly 30 feet long and inspired by a ray, it can seat up to 11 (counting the driver) and dive to depths of over 800 feet. It combines a diesel generator and 1,200-hp electric jetski powertrain to hit speeds of up to 50 mph over the water and 30 mph under it, with a maximum runtime of 54 hours combining the two systems. It also has upward folding wings to fit on a trailer — it weighs 22,000 lbs, so plan on having a beefy hauler — and boasts additional features like adaptive lighting, an automated life support system, and air conditioning. We're assuming the torpedo launchers are for military use only.