By mid-1941, the British Admiralty was faced with the fact that there was no full-fledged fighter on the decks of British aircraft carriers - the Sea Hurricane had little chance against new modifications of the 109th Messer. However, transforming the Supermarine Spitfire into a full-fledged carrier-based fighter proved difficult. First, the Spitfire's design was much more extreme in strength and could not withstand landings at high vertical speeds. In addition, the chassis, unlike the Hurricane, had a narrow track, a low margin of safety and was not suitable for deck landings.
Operations at Humble redesigned in 1942 and the rest were modified at the Supermarine plant. About 140 Spitfires Mk V were redesigned and designated Sefire Mk IB *. An additional 48 new Mk IB Sifiers built Cunliffe-Owen Aircraft.
All Sefires Mk IB had a non-folding wing, clipped like on the Mk VB, and this type of wing was installed on all brands of converted Spitfires. Wing "B" was equipped with two 20-mm cannons and four 7.7-mm machine guns, while later appeared rare Mk ICs, which had four 20-mm guns, but the weight of heavy weapons and ammunition increased.
Following the Mk IB, they released 372 Sefire Mk IIС, similar to the previous brands, but using the C wing and installing catapult stops. This version was built in two versions: by Supermarine (262) as F.Mk IIC and by Westland as L.Mk IIC, later released a version for low altitudes. The LR.Mk IIС sub-variant carried the F.24 camera for reconnaissance.
The Seafire Mk IIC began delivery in June 1942, when 12 aircraft entered Squadron 807. They, along with the Seafires, which entered the 801st squadron in September, were relocated in February 1943 to the aircraft carrier Furious, which took part in the Allied offensive in North Africa in November 1942. By the end of 1942 six squadrons received "Seifiers", among them: 808th, 880th, 884th and 887th. During 1943, the 809th, 886th, 894th, 895th, 897th and 899th squadrons were re-equipped, while the 833th, 834th, 842th and 879th squadrons, operating from escort aircraft carriers, limited to six "Seafires" each.
The next variant, the Sefire Mk III, had a manually folded wing, fixed above the cannon mount and with tips folded down. This made it possible to use the aircraft carrier lift for the Seafires and made it more convenient to place them on the deck. The Sefire Mk III prototype was converted from the Mk IIC, and under the new brand it was put into production in 1943, a total of 1220 units were produced. from November 1943 to July 1945: 870 machines by Westland and 350 by Cunliff-Owen.
The Seafire Mk III was built in three versions: a fighter (F.Mk III), a low-altitude fighter (L. Mk III) and a low-altitude reconnaissance (LR. Mk III), the latter had vertical and panoramic aerial cameras, as on LR. Mk IIC, a 136-liter jettisonable outboard fuel tank under the fuselage increased the range from 748 to 1167 km.
A large number of Sifires took part in operations in the Mediterranean.
* - originally the marine Spitfire had the name Sea Spitfire, but this name did not catch on in favor of the more euphonious Seafire - Seafire.