German submarine U-603 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II.She was laid down on 27 February 1941 by Blohm & Voss, Hamburg as yard number 579, launched on 16 November 1941 and commissioned on 2 January 1942 under Kapitänleutnant Kurt Kölzer.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-603 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 Brown, Boveri & Cie GG UB 720/8 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-603 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 5th U-boat Flotilla on 2 January 1942, followed by active service on 1 December 1942 as part of the 1st Flotilla for the remainder of her service.
In five patrols she sank four merchant ships, for a total of .
On 4 December 1942 she was returning to base when she spotted a convoy and attacked by convoy escorts, but not before reporting to base and calling in support boats.
On 8 July 1943 she was attacked by a RAF Catalina with depth charges and slightly damaged.
On 13 October 1943 an Avenger from dropped a FIDO Homing Torpedo but she successfully evaded the attack.
On 21 February 1943, while operating against Convoy ON 166, she jointly attacked the Norwegian motor tanker Stigstad with . U-332 hit her first with one torpedo, closely followed by two further torpedoes from U-603 which broke her back; sinking her in 15 minutes.
Two nights later she finished off the straggling Norwegian motor tanker Glittre with two torpedoes.
Now under the command of Oberleutnant zur See Rudolf Baltz, U-603 attacked convoy HX 237 and successfully sank the Norwegian motor vessel Brand on 12 May 1943.
U-603 took part in 13 wolfpacks, namely:
U-603 has been missing since 19 February 1944 in the North Atlantic.
U-603 was sunk on 1 March 1944 in the North Atlantic in position 48.9167°N -36°W, by depth charges from . The attack was actually against a non-submarine target.
| Date | Ship Name | Nationality | Tonnage (GRT) | Fate[1] | |
|---|---|---|---|---|---|
| 21 February 1943 | Stigstad |  Norway | 5,964 | Sunk | |
| 23 February 1943 | Glittre | Norway | 6,409 | Sunk | |
| 16 March 1943 | Elin K | Norway | 5,214 | Sunk | |
| 12 May 1943 | Brand | Norway | 4,819 | Sunk |