A high-speed launch (HSL) is a type of military boat typically used for air-sea rescue operations. The British Royal Air Force (RAF) and others used HSLs especially during World War II.
The 64 ft. high-speed, air/sea rescue launch built by British Power Boat Company (BPBC) was one of the earliest high-speed offshore rescue vessel used by the Royal Air Force.[1] The prototype, numbered 100, gave its name to the class as the "100 class"; High Speed Launch 102 is the only surviving boat from that class.[1] It was tested in 1936 and production boats were delivered in 1937.[2]
Later designs included the 1941 Type Two 63 ft HSL "Whaleback", an adaptation of a motor anti-submarine boat, the first HSL to include gun turrets.[3] British Power Boat chief designer George Selman later designed the 68 ft. "Hants & Dorset" [4]
By May 1944, The RAF had 130 HSLs.[5]