Born out of a requirement of the ''[[Kaiserliche Marine]]'' (Imperial Navy) for a [[seaplane]] fighter to defend its air bases, the Rumpler 6B was, like its contemporaries the [[Albatros W.4]] and [[Hansa-Brandenburg KDW]], an adaptation of an existing landplane design. Unlike its competitors derived from single-seat fighters, Rumpler's new aircraft was based on the company's two-seat [[Rumpler C.I|C.I]] reconnaissance aircraft.<ref>Herris 2012, pp. 12, 36</ref> The 6B retained the C.I's robust wooden and fabric [[fuselage]] with a steel-tube framework reinforcing the forward fuselage, although the [[Air observer|observer's]] [[cockpit]] was [[Aircraft fairing|faired]] over. The installation of the water-cooled {{cvt|160|hp|adj=on}} [[Mercedes D.IIII]] engine remained the same with the [[Radiator (engine cooling)|radiator]] mounted to the underside of the upper wing and the "chimney" exhaust protruding above the level of the upper wing. The [[Biplane#Bays|two-bay wings]] were unaltered although their [[Stagger (aeronautics)|stagger]] was revised with the upper wing moved forward to compensate for the removal of the observer, his armament and the weight of the two [[Float (nautical)|floats]]. These were connected to the fuselage by steel-tube [[Bracing (aeronautics)|V-struts]]. A larger [[rudder]] was fitted to offset the increased side area caused by the addition of floats. In the production aircraft, the area of the [[horizontal stabilizer]]s was slightly reduced. The armament consisted of a fixed, forward-firing 7.92 mm (.312 in) [[MG 08|LMG 08/15 "Spandau"]] [[machine gun]].<ref>Lamberton, p. 164</ref>
The initial version of the fighter was the '''6B1'''. A total of 39 of these were produced, with all but one of the number having been delivered by the end of May 1917. A new version of the basic design, the '''6B2''', was introduced in October 1917. These aircraft retained the [[Mercedes D.III]] engine, but otherwise they were based on the [[Rumpler C.IV|C.IV]], with larger dimensions and more rounded horizontal tail surfaces. In spite of the decrease in performance, 49 of this type were delivered between October 1917 and January 1918, during which time the remaining 6B1 also left the factory.<ref>Herris 2014, p. 28</ref>
