The 6B1s were reasonably successful in combat, able to hold its own against enemy land-based aircraft, but they lacked the advantages offered by the new two-seat floatplane fighters entering service when the 6B2 became available.

After the war, the Kingdom of Serbs, Croats, and Slovenes inherited two of the 6Bs purchased by Austro-Hungarian Empire while the Netherlands used one aircraft that it had interned in 1917.

Born out of a requirement of the Imperial Navy for a seaplane fighter to defend its air bases issued in May 1916, the Rumpler 6B was, like its contemporaries the Albatros W.4 and Hansa-Brandenburg KDW, an adaptation of an existing landplane design.

A larger rudder was fitted to offset the increased side area caused by the addition of floats.

The fighter intercepted and shot down a twin-engined British Caudron G.4 bomber returning from a bombing mission on Sint-Denijs-Westrem Airfield in Occupied Belgium on 7 September.

[5] Flugmeister Karl Meyer damaged a Sopwith Pup fighter of the Royal Naval Air Service on 1 February 1917 and forced it to make an emergency landing on the beach near Bredene, Occupied Belgium.

An inventory taken on 12 February showed the three prototype 6B1s and five production models assigned to Zeebrugge, one of which was armed with two machine guns.

The following morning, three 6B1s from Ostende escorted 23 Gotha G.IV heavy bombers as they returned from bombing England.

Missions included an unsuccessful search for survivors of the torpedo boat SMS G 96 that had struck a naval mine and sunk on 26 June and escorting bombers on their return trip from England on 4 July.

[6] The fighters were probably relegated to training duties for the rest of the war[7] as the Naval Air Service had come to prefer the two-seat floatplane fighters like the Hansa-Brandenburg W.12 by this time because the extra crewman could assist the pilot with over-water navigation and operate a wireless transmitter, things that the single-seat aircraft like the 6B could not do.

[10] Four 6B2s were sold to the Imperial and Royal Navy (Kaiserlich und königlich Kriegsmarine) in mid-1918 and were mostly used for maritime reconnaissance.

[13][14] During the Finnish Civil War, the anti-communist White Army ordered one 6B1 and seven other aircraft from Germany in February 1918.

[17][18] A 6B2 was interned in 1917[19] and later served with the Netherlands Naval Aviation Service (Dutch: Marineluchtvaartdienst) with the serial number U1.

On 2 September 1922, a 6B2 was one of six seaplanes to fly from Kumbor to Split, Croatia, where the aircraft's pilot, Lieutenant Commander Glauko Prebanda, performed an aerobatics display.

[22] Data from The Complete Book of Fighters: An Illustrated Encyclopedia of Every Fighter Built and Flown;[23] Die deutschen Militärflugzeuge 1910–1918;[24] Rumpler Aircraft of WWI: A Centennial Perspective on Great War Airplanes[7]General characteristics Performance Armament