Converted from Spitfire Mk VBs ( some of which were originally Spitfire Mk Is) the Seafire Mk IB had a strengthened airframe to accomodate
an A-frame arrester hooh beneath the rear fuselage for carrier opperations. One hundred and sixty six such aircraft were converted.
Although not ideal as the arrester hook could not be retracted once lowered and the undercarriage was barely adequate for heavy
carrier landings. At last the Royal Navy had a Spitfire