Homemade submarine can stay submerged for 10 hours

When’s the last time you hung out in a homemade submarine that’s been submerged underwater? You’ve never? Well, an inventor named Zhang Wuyi from China recently came up with his own submarine that let him do just that. Made from a custom-built hull, and a viewing dome for peering out of the underwater vehicle, it can travel at speeds of up to 12 mph (20km/h) and stay submerged for up to 10 hours at a time.

While it wasn’t revealed how Zhang made this possible, apparently his recent demonstration at a lake in Hubei Province earlier this week was so impressive that it convinced a wealthy local to order one on the spot. Why would anyone need their own submarine is a mystery, but hey – if you’re thinking about building your own submarine, just know that it’s possible.