The F.46 was essentially a naval version of the Spitfire 22 with a teardrop-shaped canopy and a shortened fuselage at the rear, but without the capability for wing folding. Most of the F.46s were fitted with the larger tail units, which were also used on Supermarine’s new piston fighters, the Spiteful and Seafang, that were based on the Spitfire. Supermarine manufactured the entire production run of the F.46 at its South Marston facility. However, only 24 out of the 200 ordered Mk 46s (LA541-LA564) were built since the absence of wing folding made it just another interim variant leading up to the definitive Mk 47. TM383 was the prototype for the Mk 46.