|Ordered:||15 August 1940|
|Laid down:||18 August 1941|
|Launched:||31 March 1942|
|Commissioned:||5 August 1942|
|Fate:||Scuttled 26 August 1944 in Bordeaux, later raised and broken up in 1947|
|Class and type:||Type IXC/40 submarine|
|Height:||9.60 m (31 ft 6 in)|
|Draught:||4.67 m (15 ft 4 in)|
|Test depth:||230 m (750 ft)|
|Complement:||4 officers, 44 enlisted|
|Identification codes:||M 10 459|
Laid down on 18 August 1941 by Deutsche Schiff- und Maschinenbau AG (DeSchiMAG) of Bremen as yard number 1028, she was launched on 31 March 1942 and commissioned on 5 August under the command of Oberleutnant zur See Siegfried Lüdden.
The boat carried out three patrols and she was a member of three wolfpacks. She sank eight ships and one warship; she also damaged one ship.
She was scuttled at Bordeaux, France in August 1944. The wreck was broken up in 1947.
German Type IXC/40 submarines were slightly larger than the original Type IXCs. U-188 had a displacement of 1,144 tonnes (1,126 long tons) when at the surface and 1,257 tonnes (1,237 long tons) while submerged. The U-boat had a total length of 76.76 m (251 ft 10 in), a pressure hull length of 58.75 m (192 ft 9 in), a beam of 6.86 m (22 ft 6 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.67 m (15 ft 4 in). The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4,400 metric horsepower (3,240 kW; 4,340 shp) for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1,000 shaft horsepower (1,010 PS; 750 kW) for use while submerged. She had two shafts and two 1.92 m (6 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).
The submarine had a maximum surface speed of 18.3 knots (33.9 km/h; 21.1 mph) and a maximum submerged speed of 7.3 knots (13.5 km/h; 8.4 mph). When submerged, the boat could operate for 63 nautical miles (117 km; 72 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 13,850 nautical miles (25,650 km; 15,940 mi) at 10 knots (19 km/h; 12 mph). U-188 was fitted with six 53.3 cm (21 in) torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one 10.5 cm (4.13 in) SK C/32 naval gun, 180 rounds, and a 3.7 cm (1.5 in) SK C/30 as well as a 2 cm (0.79 in) C/30 anti-aircraft gun. The boat had a complement of forty-eight.
The boat's first victim was an old 'four stacker' destroyer, HMS Beverley in mid-Atlantic on 11 April. Less than a month later, the inbound submarine was attacked by an Armstrong-Whitworth Whitley of No. 612 Squadron RAF in the Bay of Biscay on 2 May. The Commander and one crewman were wounded. The crewman died in hospital in Paris on 12 May.
U-188 docked at Lorient in occupied France on 4 May.
Having left Lorient on 30 June 1943, U-188 headed for the Indian Ocean. She sank Cornelia P. Spencer about 300 nmi (560 km; 350 mi) off the coast of Somalia on 21 September.
She was also successful when she damaged Britannia in the Gulf of Oman on 5 October. This ship was held together by wires and chains on the orders of the master who was known as the 'crazy Norwegian' by the British naval authorities in Bombay. The ship loaded 6,000 tons of oil in Abädän, Iran. She was eventually repaired in Baltimore in March 1944.
U-188's third and final foray was her longest and most successful. Operating off the Horn of Africa, she sank seven ships in a 171-day patrol. Two of them, Fort la Maune and Samouri were sent to the bottom with no casualties. It was a different story concerning the fate of the Chinese registered Chung Cheng. Twenty men out of seventy-one were lost. The ship sank quickly, probably due to her cargo of 8,350 tons of ilmenite ore.
U-188 was scuttled in Bordeaux to prevent her being captured by the advancing Allies on 20 August 1944. The wreck was broken up in 1947.
|11 April 1943||HMS Beverley||Royal Navy||1,190||Sunk|
|21 September 1943||Cornelia P. Spencer||United States||7,176||Sunk|
|5 October 1943||Britannia||Norway||9,977||Damaged|
|20 January 1944||Fort Buckingham||United Kingdom||7,122||Sunk|
|25 January 1944||Fort la Maune||United Kingdom||7,130||Sunk|
|26 January 1944||Samouri||United Kingdom||7,219||Sunk|
|26 January 1944||Surada||United Kingdom||5,427||Sunk|
|29 January 1944||Olga E. Embiricos||Greece||4,677||Sunk|
|3 February 1944||Chung Cheng||China||7,176||Sunk|
|9 February 1944||Viva||Norway||3,798||Sunk|