Some people build their own cars, this Russian man built his own submarine. It really works and has survived long underwater trips. Amazing.
This Russian man from St. Petersburg got his personal submarine. He built it himself and it is the smallest submarine in Russia, officially registered as a boat by Russian boat registry and has got it’s own personal name and number.
He can make an underwater trip from St. Petersburg to Helsinki, Finland and back without stops, and he can go as fast as four knots.