were slightly larger than the original Type IXCs. U-548 had a displacement of when at the surface and while submerged. The U-boat had a total length of, a pressure hull length of, a beam of, a height of, and a draught of. The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to. The submarine had a maximum surface speed of and a maximum submerged speed of. When submerged, the boat could operate for at ; when surfaced, she could travel at. U-548 was fitted with six torpedo tubes, 22 torpedoes, one SK C/32 naval gun, 180 rounds, and a SK C/30 as well as a C/30 anti-aircraft gun. The boat had a complement of forty-eight.
Service history
1st patrol
U-548s first patrol began with her departure from Kiel on 21 March 1944. She passed through the gap separating Iceland and the Faroe Islands before heading out into the Atlantic Ocean. The boat was involved in a rather bizarre incident on the night of 3 May when a B-24 Liberator illuminated east of Conception Bay, Newfoundland, thinking she was a U-boat. U-548 fired at the aircraft which in turn wrongly assumed they had been engaged by the ship. The real quarry aborted her attack and escaped. The boat was the target of an unsuccessful hunt by Allied escorts after the sinking of on 7 May south of Cape Race,. She entered Lorient, on the French Atlantic coast, on 24 June 1944.
2nd and 3rd patrols
On her second foray, U-548 lost a man overboard,, during a crash-dive on 30 August 1944. Reversing the course of her first patrol, she arrived at Bergen in Norway, on 25 September. Having moved to Hölen in Norway, the boat began her third sortie on 7 October 1944. She docked at Flensburg on the 12th.
4th patrol and loss
By now, U-548 was based at Horten Naval Base also in Norway, from where she began her fourth and last patrol on 5 March 1945. She crossed the Atlantic once more and was sunk southeast of Halifax, Nova Scotia on 19 April by depth charges from the Americandestroyer escorts and. Fifty-eight men died with the U-boat; there were no survivors.