{| |} The Savoia-Marchetti S.57 was an Italian single-engine biplane flying boat intended for aerial reconnaissance, built by Savoia-Marchetti for Regia Aeronautica after World War I. Of wooden construction with a single-step hull, with pilot and observer/gunner in tandem open cockpits in the bow, the S.57 was powered by a single 186 kW (250 hp) Isotta-Fraschini V6. The observer had a single ring-mounted 7.7 mm (.303 in) FIAT machine gun. Eighteen S.57s were accepted by Regia Aeronautica in 1925 and used as trainers.