In her unlucky career, it had the distinction of being the "most heavily damaged U-boat to successfully return to port" in World War II, suffering six botched patrols, and becoming the only submarine in which a commanding officer killed himself in combat conditions.

It is now one of four German World War II U-boats that survive as museum ships, and one of just two Type IXCs still in existence, along with U-534.

In less than one month, U-505 sank four ships: British Benmohr, Norwegian Sydhav, American West Irmo, and Dutch Alphacca for a total of 25,041 GRT.

[10] Urious was a sailing ship belonging to a Colombian diplomat, and its sinking was one of a long series of incidents that gave Colombia political grounds to declare war on Germany a year later.

53 Squadron, Royal Air Force, which made a low-level attack, landing a 250 lb (110 kg) bomb directly on the deck from just above water level.

The aircraft was hit by fragmentation from the bomb's explosion and crashed into the ocean near U-505, killing RAAF pilot Flight Sergeant Ronald Sillcock and his entire crew.

Zschech ordered the crew to abandon ship, but the technical staff (led by Chief Petty Officer Otto Fricke) insisted on trying to save her.

After sending the wounded watch officer to the supply submarine ("milk cow") U-462, U-505 limped back to Lorient on reduced power.

[14] U-505's next four patrols were all aborted after only a few days at sea, due to equipment failure and sabotage by French dockworkers working for the Resistance.

[15][16][17][18] Faults found included sabotaged electrical and radar equipment, a hole deliberately drilled in a diesel fuel tank, and faulty welds on parts repaired by French workers.

Upon returning from one botched patrol, her crew found a sign painted in the docking area reading: "U-505's Hunting Ground".

British destroyers spotted her east of the Azores on 24 October 1943, not long after crossing the Bay of Biscay, and she was forced to submerge and endure a severe depth-charge attack.

[20][21] Zschech is recorded as the only known submariner during the war to commit suicide underwater in response to the stress of a prolonged depth charging.

She again returned early to Lorient on 2 January 1944, after she rescued 33 crew members from the German torpedo boat T25, sunk on 28 December by British cruisers in the Bay of Biscay.

[25] The group sailed from Norfolk, Virginia, on 15 May 1944 and began searching for U-boats in the area in late May, using high-frequency direction-finding fixes ("huff-duff") and air and surface reconnaissance.

At 11:09 on 4 June 1944, TG 22.3 made sonar (ASDIC) contact with U-505 at 21°30′N 19°20′W / 21.500°N 19.333°W / 21.500; -19.333 (U-505 action), about 150 nmi (280 km; 170 mi) off the coast of Río de Oro,[23] only 800 yards (700 m) from Chatelain's starboard bow.

[28] Chatelain and Jenks collected survivors, while an eight-man party from Pillsbury led by Lt. Albert David came alongside the submarine in a boat and entered through the conning tower.

[23] U-boat researcher Derek Waller has written that a German crewman, Ewald Felix, helped foil the scuttling attempt.

With the U-boat moving under tow by Guadalcanal, the propellers spun as they passed through the water, turning the shafts and the driving motors.

With power from the batteries, U-505's pumps cleared out the water let in by the attempted scuttling, and her air compressors blew out the ballast tanks, bringing her up to full surface trim.

[23] Despite the capture taking place close to Allied-controlled French Morocco, Casablanca was known to be infiltrated by German spies, thus another safe port was needed to house the submarine.

On 19 June, the submarine entered the Great Sound, site of the United States Navy's Naval Operating Base in Bermuda, after a tow of 1,700 nautical miles (3,150 km; 1,960 mi).

[30] Secrecy was so important to the mission that the submarine's flag was kept under the personal care of the Commander in Chief of the Atlantic Fleet during the duration of the war.

[33] LTJG Albert David received the Medal of Honor for leading the boarding party, the only time that it was awarded to an Atlantic Fleet sailor in World War II.

Admiral Royal E. Ingersoll, Commander in Chief, US Atlantic Fleet, cited the task group for "outstanding performance during antisubmarine operations in the eastern Atlantic" and stated that it was "a feat unprecedented in individual and group bravery, execution, and accomplishment in the naval history of the United States".

Coast Guard tugboats and cutters towed the boat through the Great Lakes, making a stop in Detroit, Michigan, in July 1954.

[39] The Navy had removed the periscope and placed it in a water tank used for research at its Arctic Submarine Laboratory in Point Loma, California, where it was forgotten.

[40] By 2004, the U-boat's exterior had suffered noticeable damage from the weather, so the museum moved her to a new climate-controlled location (under ground next to the MSI) in April 2004.

Gary Moore recounts a dramatized story of the captured crew in his 2006 historical fiction book Playing with the Enemy.