The Bréguet 790 Nautilus was a prototype French three-seat coastal patrol flying-boat designed and built by Bréguet Aviation to meet a requirement from the French navy.
[1] The aircraft was powered by a 720 hp (537 kW) Hispano-Suiza 12Xirs V-12 piston engine strut-mounted above the hull, driving a pusher propeller.
[1] The first of two prototypes flew in 1939 and performed well enough that a production order for 75 was placed.
[1] The order was reduced to 45 in May 1940 in order to free production capacity for more urgently needed combat aircraft, but none were built following the German invasion.
[1][2] Data from [1]General characteristics Performance Armament