High Quality Content by WIKIPEDIA articles! RAF St Eval was a strategic airbase for the RAF Coastal Command in the Second World War (situated in Cornwall, England, United Kingdom). St Eval`s primary role was to provided anti-submarine and anti-shipping patrols off the south west coast of England. Aircraft from the base were also used for photographic reconnaissance missions, meteorological flights, convoy patrols, air-sea rescue missions and protection of the airbase from the Luftwaffe.