As part of the renamed Kriegsmarine, the boats made multiple non-intervention patrols during the Spanish Civil War in the late 1930s.

During World War II, they played a minor role in the Norwegian Campaign of 1940, Albatros being lost when she ran aground.

They helped to escort blockade runners, commerce raiders and submarines through the English Channel and the Bay of Biscay throughout 1942 and 1943.

The two surviving operational boats, Falke and Möwe, attacked Allied ships during the Invasion of Normandy in June with little success and they were sunk by British bombers later that month.

The boats were drier than the older design, but had a lot of weather helm so that they were "almost impossible to hold on course in wind and at low speed".

They carried a maximum of 321 tonnes (316 long tons) of fuel oil which gave a range of 1,800 nautical miles (3,300 km; 2,100 mi) at 19 knots (35 km/h; 22 mph).

[14] After the heavy cruiser Deutschland was bombed by Republican aircraft on 29 May 1938, Adolf Hitler ordered her sister ship, the Admiral Scheer to bombard the Republican-held city of Almería.

Together with three destroyers, Albatros, Falke and Greif made anti-shipping patrols in the Kattegat and Skaggerak from 3 to 5 October that captured four ships.

On 13, 18 and 19 November, the 6th Flotilla and one or two light cruisers met destroyers returning from minelaying missions of the English coast.

Two days later the flotilla patrolled the Skagerrak to inspect neutral shipping for contraband goods before returning to port on the 25th.

From 14 to 16 December, Seeadler and the torpedo boat Jaguar made contraband patrols in the Skaggerak, impounding six ships.

Albatros, Kondor and Möwe were assigned to support the attack on the Norwegian capital of Oslo while Falke, Greif, Seeadler were tasked to help capture Kristiansand and Aarendal on the south coast.

Albatros fired the opening shots of the invasion as she crippled a Norwegian patrol boat at the mouth of the Oslofjord leading to on the evening of 8/9 April.

Greif ferried the troops that captured the undefended town of Arendal before joining Seeadler at Kristiansand after the garrison there had surrendered.

As the heavy cruiser Lützow was proceeding to Germany without an escort two days later, she too was crippled by a British submarine off the Danish coast and all five boats responded to render assistance.

[18] Later that month Greif, Kondor and Möwe were among the escorts for minelayers as they laid minefields in the Skaggerak and the latter was torpedoed by a British submarine on 8 May.

They joined the escort force for the battleships Scharnhorst and Gneisenau and the heavy cruiser Prinz Eugen on 12 February 1942 off Cap Gris-Nez during the Channel Dash.

In September and October, Möwe was one of the escorts for German blockade runners sailing from ports in the Bay of Biscay en route to Japan.

Falke and Kondor helped to escort the Italian blockade runner, SS Cortellazzo, from Bordeaux through the Bay of Biscay on 29–30 November.

[21] Greif was working up through the first couple of months of 1943; in March, she helped to escort the battleships and other ships as they moved from Trondheim, Norway, to Altafjord.

Another Italian blockade runner, Himalaya, escorted by Kondor and three other torpedo boats, failed in her attempt to break through the Bay of Biscay when she was spotted by British aircraft and forced to return by heavy aerial attacks on 9–11 April.

Kondor began a lengthy refit in Le Havre, but was cannibalized for spare parts after the Allies landed in Normandy on 6 June.