Slowly making my way through Friedman's British Cruisers and a number of mentions have been made of the perceived importance of floatplane torpedo bombers, dive bombers, fighters and spotting aircraft. The problem was treaties and finances restricted the numbers of carriers available so station forces, a mix of heavy, light and older trade protection cruisers, were required to carry sufficient aircraft to provide a viable strike, reconnaissance and fighter cover, hence floatplane versions of many carrier and land based types were developed as well as some specific types, i.e. the Seafox.
This was primarily intended for the Far East as the battle fleets were stationed at home and in the Mediterranean with mainly cruisers in SEA, which would be required to scout and delay any Japanese offensive until heavy forces could be pivoted from the Mediterranean and aircraft, even in the absence of carriers would be vital for this. For example the HMS York, like Exeter and the Counties, had a heavy catapult amidships, but was also intended to have a light catapult forward over B turret for a fighter, scout or spotter type. The idea was scout cruisers would use their aircraft to find the Japanese, while the eight heavy cruisers would carry strike aircraft to directly attack Japanese forces and fighters to defend themselves.