German submarine U-561

German submarine U-561 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 28 February 1940 by Blohm & Voss in Hamburg as yard number 537, launched on 23 January 1941 and commissioned on 13 March 1941 under Kapitänleutnant Robert Bartels (German Cross in Gold).

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-561 had a displacement of 769 t when at the surface and 871 t while submerged. She had a total length of 67.10 m, a pressure hull length of 50.50 m, a beam of 6.20 m, a height of 9.60 m, and a draught of 4.74 m. The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2800 to 3200 PS for use while surfaced, two BBC GG UB 720/8 double-acting electric motors producing a total of 750 PS for use while submerged. She had two shafts and two 1.23 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 17.7 kn and a maximum submerged speed of 7.6 kn. When submerged, the boat could operate for 80 nmi at 4 kn; when surfaced, she could travel 8500 nmi at 10 kn. U-561 was fitted with five 53.3 cm torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm SK C/35 naval gun, 220 rounds, and a 2 cm C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.

Service history
The boat's service began on 13 March 1941 with training as part of the 1st U-boat Flotilla. During late July 1941, U-561, along with 9 other German and Italian submarines, attacked convoy OG 69 en route from Liverpool to Gibraltar. U-561 torpedoed and sank the 1,884 GRT British freighter Wrotham.

In November 1941, while travelling across the Atlantic ocean, she sunk two boats from convoy SC 53, the Meridian and the Cruisader.

She was transferred to the 23rd flotilla on 1 February 1942. In 15 patrols she sank five ships for a total of, plus one ship damaged and a second a total loss.

She was sunk by torpedoes fired from Royal Navy's HMS MTB-81 on 12 July 1943 at position 38.26667°N, 15.65°W in the Straits of Messina.

Wolfpacks
She took part in two wolfpacks, namely:
 * Bosemüller (28 August – 2 September 1941)
 * Seewolf (2 – 15 September 1941)