With the advent of the MkIX Spitfire variant and the German 109 'G' models and FW190's the MkV(b) quickly became obsolete as a front line fighter. Although still used as an escort fighter for the early excurtions over France the losses were unaceptable and another use's needed to be found for them. One such use was to convert several MkII and MkVb's to the Air Sea Rescue roll. It was found that the 'Type E' sea survival and rescue kit would fit into the underside flare chutes on the Spitfire. This kit comprised of one large and one smaller canister filled with a multi-seat dinghy, canned water, rations, a first aid kit and distress flares.
The yellow codes on this scheme are in the standard yellow of the ASR Squadrons.