Hardegen achieved the rank of Korvettenkapitän, though at the time he was Kapitänleutnant. Over his career he sank 21 ships for a total of 112,447 GRT and damaged four others for 32,516 GRT – he also sank one warship and damaged another. On 23 April 1942, following this patrol he was awarded the Knights Cross with Oak Leaves, and later the U-boat badge with Diamonds. A member of the crew of 1933 at the Naval Academy (Marineschule) in Mürwik, eastern Germany, he was only 30 at the time.
Hardegen actually began his career in the naval air force, but injuries sustained when he crashed as a pilot brought him to the U-boat arm in November 1939, at the outset of the war. His total command experience of five patrols of 240 days at sea on two submarines plus his longevity and accessibility have made Hardegen somewhat of a “darling” of U-boat research into attacks on the Americas, or at least the United States.
Hardagen’s patrols feature prominently in books such as Operation Drumbeat by Michael Gannon and Torpedo Junction by Homer Hickham, and The Fuhrer’s U-boats in American Waters by Gary Gentile (who accused Hardegen of doctoring his log). His feats are extolled on websites such as Sharkhunters of which he is a member. By all accounts Hardegen is a personable and likeable commander and veteran – he was said to have tied the shoe laces of an old merchant mariner who visited him to meet the man who sank him.
Hardegen corresponded with his victims, and took part in two particularly tragic sinkings – that of the only battle-tested armed merchant cruiser which the Americans put forth (the Atik, AK 101 aka the Caroline, in which all members of the US Navy crew and one of Hardegen’s crew perished on a stormy night) and the Muskogee, whose desperate survivors were photographed by Hardegen’s crew but never seen alive again (photos from a German magazine surfaced in a POW camp for allies and survived the war, and became the model of the Merchant Mariner’s Memorial in New York City).
In short Hardegen came to symbolize the opening attack on the Americas in the way that Werner Hartenstein and Albrecht Achilles symbolized the daring attacks in the Caribbean theater, and that Carlo Fecia di Cossato would represent the ravaging of ships off the Bahamas. He would have to be included in the iconic skippers such as Herbert Werner in his autobiographical Iron Coffins and the skipper in the fictional film Das Boot, which was loosely based on the patrols observed by a war correspondent.