The Supermarine Stranraer was a 1930s flying boat designed and built by the British Supermarine Aviation Works company principally for the Royal Air Force. They entered operations in 1937 and many were in service at the outbreak of the Second World War undertaking anti-submarine and convoy escort patrols. They were withdrawn from operational service in March 1941 but continued to serve in a training capacity until October 1942. In addition to the British-built aeroplanes, the Canadian Vickers company in Montreal, Quebec, built 40 Stranraers under licence for the Royal Canadian Air Force. The RCAF Stranraers served in anti-submarine and coastal defense capacities on both Canada's Atlantic and Pacific coasts, and remained in service until 1946. Following their withdrawal from military service, many Canadian Stranraers were sold off to fledgeling regional airlines and they served in commercial passenger and freighter operation well into the 1950s.