The U-2513 is what's known as a Type 21 German U-boat. In the 1940s, the Type 21 was a secret weapon that threatened to change the course of two wars: WWII, and then later, the Cold War. During WWII, German hopes were riding on it, and the Allies were terrified of it. After the war, the British, Americans, and Russians couldn't wait to get their hands on it. It was a weapon that had the potential to change the balance of world power and determine the outcome of the Cold War. Join our Deep Sea Detectives, John Chatterton and Richie...