The motorboat unit was initially operated by the SAAF, before being transferred to the SA Navy and later the SA Army, but this article is listed under the SA Navy group, for consistency.

Far away from enemy air force bases, South Africa's air space was ideally suited for the training of aircrews. A great deal of this training, in particular navigation and weapons delivery was conducted over the sea. Naturally there were accidents and in the days before helicopters, the rescue of downed crewmen was not as easy as it is today.

Initially the South African Air Force established 12 Motor Boat Section at Gordon's Bay in December 1939, to operate 40ft armoured target boats, known as Malgas I and Malgas II. Fitted with seven tons of armoured steel as protection, they acted as targets on the bombing and air gunnery range at Strandfontein for various Squadrons operating from Wingfield, Brooklyn and Yougsfield. Recognising the need to provide some sort of rescue service the SAAF ordered a single 64 ft High Speed Launch powered by three Rolls Royce Merlin engines. This boat was christened Malmok (the black browed Albatross) and was so successful that an order was placed for more of the same.

The demand for Merlin engines needed to power the Spitfires and Hurricanes, vital to Britain's defence meant that the order could not be met. The South African Purchasing Commission, in Washington was tasked with finding suitable vessels. John Glen (Jock) Finlay (later founder and head of Safmarine) was authorised to acquire eight rescue craft capable of 40 knots and containing a dispensary with accommodation for six beds. Within a short space of time the Miami Shipbuilding Corporation had built a 63 foot wooden boat capable of achieving 42 knots using four Kermath Raider engines. A contract for eight boats was awarded and the first four, designated R1 to R4 arrived in Cape Town on 20 May 1941. These boats were followed by the second four, R5 to R8, which arrived on 24 July 1941. In January 1944 boats R9 to R20 were delivered, being the improved Miami Craft Mk II.

One of the original motorboats - R4.