This documentary traces the history of the Short Sunderland Flying Boat, from its introduction to service in the RAF in 1938 it was to become one of the longest serving careers of any front-line aircraft. The Sunderland was one of the very few types to remain in operational service through the Second World War and the only RAF aircraft to perform front-line duties for the whole of the Korean War. When it finally retired in 1959, it had served for a total of twenty one years and had built up a reputation as a tough and reliable workhorse.