First patrol

U-52's first patrol began with her departure from Kiel on 19 August 1939, well before the outbreak of war. She crossed the North Sea and headed for the Atlantic Ocean via the 'gap' between Iceland and the Faroe Islands. The most southerly point of the patrol was reached on 1 September, the same day that Germany began the invasion of Poland.

Second patrol

After a series of short trips from Kiel to the German-administered island of Helgoland, (also known as Heligoland) and then Wilhelmshaven, the boat left Helgoland on 27 February 1940 and arrived at Wilhelmshaven on 4 April.

Third patrol

Three days later, U-52 began her third sortie. It was very similar to her second; but success continued to elude her. She crossed the North Sea and swept the area between the Faroes and Shetland Islands.

Fourth patrol

Having sailed in a southerly direction to the west of Ireland, the boat sank The Monarch 60 nautical miles (110 km; 69 mi) west of Belle Ile in the Bay of Biscay on 19 June 1940. Moving further into the Bay, U-52 came across the Ville de Namur. At first the Germans were under the impression that large wooden structures on deck were for weapons, when they were stables for horses. Nevertheless, the vessel was sunk; she went down in five minutes.

She also sank the Hilda on 21 June and the Thetis A. on 14 July. The latter vessel had already been attacked, but the torpedo used malfunctioned, (a common occurrence in the early months of the war).

Fifth patrol

Foray number five was in terms of tonnage sunk, her most successful; she destroyed the Gogovale on 4 August 1940 about 300 nautical miles (560 km; 350 mi) west southwest of Bloody Foreland (County Donegal in Ireland).^[3] On about the same day the submarine was badly damaged by British escorts; repairs took four months to implement.

Sixth patrol

Her tally rose steadily with the demise of the Tasso and the Goodleigh on the same day (2 December 1940). Both ships went to the bottom about 360 nautical miles (670 km; 410 mi) west of Bloody Foreland.

Seventh patrol

Continuing her hunting in mid-Atlantic, U-52 sank the Ringhorn on 4 February 1941 and the Canford Chine about 165 nautical miles (306 km; 190 mi) southwest of Rockall, (a tiny outcrop), on the tenth. There were no survivors from the second ship.

Eighth patrol

She sank the Saleier on 10 April 1941. The ship sank in 15 seconds but the whole crew of 63 survived.^[4]

Her last recorded victim was the Ville de Liège, a Belgian-registered vessel which was successfully attacked about 700 nautical miles (1,300 km; 810 mi) east of Cape Farewell, (southern Greenland)^[5] on 14 April.