During her career U-30 was involved in eight war patrols, under the command of Kptlt. Fritz-Julius Lemp.
U-30's career began ingloriously, when on 3 September 1939 she sank the 13,581 ton passenger ship SS Athenia, the first ship sunk in World War II. Lemp's career was almost wrecked, but he pleaded it was a genuine error - mistaking her for an armed merchant cruiser, which he claimed was zig-zagging.
U-30 went on to become very successful, sinking 16 merchant ships, totaling 86,165 gross register tons (GRT), and one auxiliary warship of 325 GRT. U-30 also damaged one ship totaling 5,642 GRT, and damaged the British battleship HMS Barham.
Retired from front-line service in late 1940, U-30 was assigned to training flotillas for the rest of World War II, and was used in the last months as a range boat. It was scuttled on 4 May 1945 in Kupfermühlen Bay and the wreck was later broken up in 1948.
KMS U-30 in The War That Came Early
Under the command of Julius Lemp, the U-30 was successfully used in World War II. Indeed, it was so successful that the German High Command were able to forgive Lemp after he accidentally sank the Athenia, an American luxury liner.
In early 1939, a new weapon was installed aboard the U-30.