The U-47 was the most effective German Kriegsmarine ocean submarine during the Second World War. It entered service in 1938. The ship became famous for her daring attack on the British Navy base, during which she sank the battleship HMS Royal Oak. During their service, the U-47 crew sank a total of 32 vessels with a total tonnage of 202,514 tons. The ship went missing in the Atlantic in March 1941, symbolically ending the period of success of German submarines. The U-47 was a medium-sized vessel intended for long-term patrols in the waters of the oceans. It had 857 tons of displacement when submerged. On the surface, its range was 6,500 nautical miles, which it could cover at a speed of 12 knots. The safe immersion depth was 220 meters. It was sailing under the water at a maximum speed of 8 knots. It was armed with 14 torpedoes that could be fired from 5 tubes. The crew consisted of 44 sailors and officers.