German submarine U-653 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II.She was laid down on 9 April 1940 by Howaldtswerke, Hamburg as yard number 802, launched on 22 March 1941 and commissioned on 25 May 1941 under Kapitänleutnant Gerhard Feiler.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-653 had a displacement of 769t when at the surface and 871t while submerged. She had a total length of 67.1m (220.1feet), a pressure hull length of 50.5m (165.7feet), a beam of 6.2m (20.3feet), a height of 9.6m (31.5feet), and a draught of 4.74m (15.55feet). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of NaNPS for use while surfaced, two Siemens-Schuckert GU 343/38–8 double-acting electric motors producing a total of 750PS for use while submerged. She had two shafts and two 1.23abbr=onNaNabbr=on 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-653 was fitted with five 53.30NaN0 torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.82NaN2 SK C/35 naval gun, 220 rounds, and a 2sp=usNaNsp=us C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.
The boat's career began with training at 1st U-boat Flotilla on 25 May 1941, followed by active service on 1 December 1941 as part of the 1st Flotilla for the remainder of her service.
In nine patrols she sank three merchant ships, for a total of, and one warship of 840 tons.
In a determined attack, between 22:00 on 23 February 1943 and daybreak the following morning, U-653, together with, and, came in one after the other against Convoy ON 166.
U-653 fired seven torpedoes at, and missed, the British freighter Delilian, but succeeded in striking the 9,382-GRT Dutch motor vessel Madoera. Against the odds, Madoera stayed afloat and reached St. John's seven days later, but not before some of her crew had abandoned ship and made for the lifeboats. This resulted in the Dutch ship's chief officer being captured by .
U-653 was sunk on 15 March 1944 in the North Atlantic in position 53.7667°N -59°W, by depth charges from Fleet Air Arm Swordfish, and . All hands were lost.
U-653 took part in 16 wolfpacks, namely:
| Date | Ship Name | Nationality | Tonnage[1] | Fate[2] | |
|---|---|---|---|---|---|
| 28 February 1942 | Leif |  Norway | 1,582 | Sunk | |
| 17 May 1942 | Peisander |  United Kingdom | 6,225 | Sunk | |
| 7 June 1942 | 840 | Sunk | |||
| 24 February 1943 | Madoera |  Netherlands | 9,382 | Damaged | |
| 12 March 1943 | Thomas Hooker |  United States | 7,176 | Sunk |