Reinhard Scheer
After their commissioning, "Cöln" and "Dresden" joined the High Seas Fleet. They were assigned to the II Scouting Group, alongside the cruisers , , , , and . The ships were in service in time for the major fleet operation to Norway in 23–24 April 1918. The I Scouting Group and II Scouting Group, along with the Second Torpedo-Boat Flotilla were to attack a heavily guarded British convoy to Norway, with the rest of the High Seas Fleet steaming in support. The Germans failed to locate the convoy, which had in fact sailed the day before the fleet left port. As a result, Admiral Reinhard Scheer broke off the operation and returned to port.