Throughout World War II submarine warfare was widespread and merciless, but after the war it just seemed to... stop. While submarines continue to be an integral part of navies around the world, there have been only 2 submarines that sank enemy ships in combat since... | Dark Documentaries

Nazi Germany's fleet of submarines terrorized the oceans during WWII. See what life was like on a ship in the crosshairs on Hell Below: https://bitly.com/2xv5mhv | Smithsonian Channel Aviation Nation