The Gotha WD.3 (for Wasser Doppeldecker - "Water Biplane") was a reconnaissance seaplane built in prototype form in Germany in 1915. Since 1913, Gotha had been manufacturing a series of reconnaissance seaplanes for the German Navy, initially patterned on the Avro 503. These were intended as unarmed scouts, but as World War I unfolded, it became desirable to arm this type of aircraft. In the days before the development of the interrupter gear, the most effective way to mount a gun with a forward firing arc was to dispense with a conventional fuselage, relocate the engine to the rear of a nacelle that also carried the cockpit, weapons, and wings, and carry the tail on booms stretching back either side of the engine and propeller installation. Gotha had built land-based copies of the French Caudron G.3 in a similar configuration as the LD.3 and LD.4 and now used the same layout for the WD.3. Only a single prototype was built, however, and Gotha's subsequent efforts with this arrangement would focus on twin-engine aircraft.