Type Two HSL is a term for a class of British large motor boats from the Second World War. The length of a single unit of this type was 19 meters, and the displacement did not exceed 22 tons. The drive was provided by 3 Napier Sea Lion engines with 500 HP each. The maximum speed was up to 36 knots, and the armament of a single boat of this type usually consisted of two 7.7 mm machine guns.
The Type Two HSL motor boats were designed by Hubert Scott-Paine in 1937 for the British Power Boat Company. When designing this type of boat, particular emphasis was placed on the highest possible maximum speed, maneuverability and functionality. Boats of this type were used on a large scale by the RAF Sea Rescue Service, a special service dedicated to the rescue of British and Allied pilots who were forced to land on the water. The first boats of this type entered service in mid-1940, and their production continued in 1940-1942. In total, about 70 boats of this type were built. It is worth noting that specially modified Type Two HSL boats took part in the Dieppe rally in 1942.
During World War II, the RAF's Maritime Rescue Service (ASR) played a key role in rescuing thousands of highly trained Allied aircraft crews by carrying out rescue operations around the British Isles as well as in other maritime regions where war was raging. Working closely with the Royal Navy, the ASR used both airplanes and high-speed boats to carry out its missions. One of the most famous was the British Power Boat Company Type 2 63 ft HSL, known as the 'Whaleback' - 'whale back' due to its characteristic curved deck. Another, equally frequently used term was 'Spitfire ASR'. The unit, designed in 1937 by Hubert Scott-Paine, began entering service in mid-1940. Initially, the defense equipment consisted of two Armstrong-Whitworth anti-aircraft turrets, each with a single Vickers machine gun. After the fatal raid on Dieppe in August 1942, when several units were destroyed, it was decided to install two additional machine guns, one on both sides, and a 20mm caliber cannon in the aft section, specially reinforced for assembly purposes. The armor, especially of the cabins, was also expanded, and although this naturally increased the weight of the unit, it still developed a fully satisfactory top speed of 36 knots thanks to the 500hp Napier Sea Lions (a redesigned aircraft engine) and had a range of about 500 miles at an average speed of 25 knots. The crew consisted of 9 people, including the captain and medical personnel. The ASR bases were mainly located on the south-east coast of Great Britain, known as Hellfire Corner, due to the high number of accidents caused by continuous air fighting over the English Channel and the North Sea. Initially, ASR rescue units were painted in bright yellow - black colors for better visibility, however, due to the increasing frequency of attacks by the German air force, it was considered necessary to use camouflage gray colors. In 1944, the ASR RAF had more than 300 fast lifeboats at its disposal, which made it possible to cover the entire coast of Great Britain and many other important areas in the Mediterranean or even the Indian Ocean. Also, Malta, after the attacks in 1941, decided to establish the ASR base in the same year, and only by December 1942, 125 valuable crews were saved.