Submarine Products Ltd (1959−1990) was a diving gear manufacturer, with a factory in Hexham in Northumberland, England. It was founded in 1959 by Lieutenant-Commander Hugh Oswell. Until the late 1950s, the British Siebe Gorman company patents kept aqualungs expensive in Britain, and many British sport divers had to use home-made breathing sets and ex-armed forces or ex-industry rebreathers. Some became expert at home-making scuba diving demand regulators from industrial parts such as Calor Gas regulators.