Clearly ahead of its time, the fascinating Gotha-built Ursinus single-seat floatplane fighter never progressed beyond the sole prototype. Powered by a 150hp Benz, the machine was designed during the latter part of 1915. Central to the Ursinus concept was the use of the two retractable main floats, that, once aloft, tucked up to form the aircraft's belly to reduce drag by a considerable amount, along with providing a buoyant hull in the case of an emergency forced landing on water. Just how good this machine would have proved from an operational stand-point remains a matter of conjecture, as the fighter was lost during flight testing in 1916. Somewhat surprisingly for a young industry that was usually quite quick to pick up on good ideas, only two subsequent aircraft proposed for production, the Blackburn B-20 of 1940 and Convair's XF2Y-1 Seadart of 1953, were to employ a comparable form of float retraction.