Single-seater day and night fighter. Supermarine Type 178 11 (1932) – Three-engined monoplane flying boat. Known as the Military Air Yacht. Supermarine Type 178 12 (1932) – Single-seater biplane day and night fighter. Modified from the Type 178 10. Supermarine Type 178 14 (1932) – Single-seater monoplane day and night fighter. Modified from the Type 178 10. Supermarine Type 180 (1929) – Four-engined civilian flying boat. Supermarine Type 182 (1931) – General purpose civilian high-wing monoplane. Supermarine Type 183 (1931) – General purpose civilian low-wing monoplane. Supermarine Type 232 (1934) – Four-engined flying boat to Air Ministry specification R.2/33. Supermarine Type 238 (1934) – Biplane flying boat to Air Ministry specification R.2/33. Supermarine Type 239 (1934) – Four-engined flying boat to Air Ministry specification R.2/33. Supermarine Type 240 (1934) – Twin-engined coastal reconnaissance landplane. Supermarine Type 302 (1935) – Four-engine flying boat for Imperial Airways Supermarine Type 305 (1935) – Two-seater day and night fighter with all four guns in a turret to Air Ministry specification F.9/35. Supermarine Type 306 (1935) – Four-engined high wing monoplane flying boat. Supermarine Type 307 (1935) – Seagull V with Pegasus VI engine. Supermarine Type 308 (1935) – Long range flying boat to Air Ministry specification R.12/35. Supermarine Type 310 (1935) – Long range flying boat. Supermarine Type 312 (1936) – Single seat day and night fighter to Air Ministry specification F37/35. Supermarine Type 313 (1936) – Single seat day and night fighter to Air Ministry specification F37/35. Supermarine Type 314 (1936) – High performance flying boat to Air Ministry specification R.1/36. Supermarine Type 315 (1936) – Walrus for Argentina. Supermarine Type 316 (1937) – Four-engined heavy bomber to Air Ministry specification B12/36. Supermarine Type 317 (1937) – Four-engined heavy bomber with Hercules engines to Air Ministry specification B12/36. Abandoned after prototypes destroyed by German bombing attack. Supermarine Type 318 (1937) – Four-engined heavy bomber with Merlin engines to Air Ministry specification B12/36. Supermarine Type 319 (1937) – Two-seater turret fighter, developed from F11/37 Supermarine Type 305 (1938) – Design project for a turret armed derivative of the Spitfire Supermarine Type 323 (1938) – Speed Spitfire. Supermarine Type 324 (1938) – Twin Merlin engined, tricycle undercarriage fighter based on Spitfire wing and fuselage to Air Ministry specification F18/37. Supermarine Type 325 (1938) – Twin-engined fighter to Air Ministry specification F18/37. Version of the Type 324 but with two pusher engines. Supermarine Type 327 (1938)