Service overseas and post-war

Home waters were not the only place the ASR operated. Malta improvised an ASR service, and in 1941 whilst under ceaseless attack, a local ASR launch rescued 30 RAF pilots, their return to the island no doubt proving a vital factor in its defence. In the Middle East, a local ASR flight operated since Italy's entry into the war and by the end of the desert campaign had achieved some excellent results. Much of its work was done in the desert where stranded pilots and bomber crews were just as helpless as if they were in the Mediterranean.

ASR development in the Far East was hampered by a shortage of equipment as the European war made extension of the ASR service into this region impossible following the Japanese advance into Burma at the end of 1941. There was however, one ASR launch based at Singapore and fitted out with home-made equipment, and this successfully rescued 23 pilots between December 1941 and January 1942.

Post World War II, the ASR services rapidly diminished in size, if not importance. Even the ASR shoulder flash, worn with great pride by the rescue crews was withdrawn to universal dismay. The remaining high-speed launches were redesignated as Rescue/Target-Towing Launches (RTTLs) and in 1948, all RAF craft longer than 68 feet became HMAFVs (His Majesty's Air Force Vessel) and were allowed to wear the Union Flag, an honour previously reserved exclusively for ships of the Royal Navy. At around the same time, the RAF element of the combined Air Sea Rescue Service was formed into a separate arm of the RAF known as the RAF Marine Branch. The Marine Branch survived until well after the introduction of the helicopter, and the last unit was not disbanded until April 1986.

A year previously, the United Kingdom had signed up to the Chicago Convention charter from which was born the International Civil Air Organisation (ICAO). With the increase in post-war commercial flying, especially across the Atlantic, the RAF and its Marine Craft Units (MCUs) was asked to fulfil the UK's obligations to provide a search and rescue service.