The Convention on the International Maritime Satellite Organisation, plus Operating Agreement, is adopted in London.

Since the launch of the world's first telecommunications satellite, Telstar, in 1962, the International Maritime Organisation (IMO) recognised the potential for a satellite communications system that would aid distress situations at sea. In February 1966, the IMO's Maritime Safety Committee (MSC) began to investigate the requirements for a satellite systems entirely devoted to maritime purposes. In 1973, the IMO held a conference to establish a maritime communications systems based on satellite technology. The conference first began in 1975, and after three sessions, the Convention on the International Maritime Satellite Organisation (Inmarsat) was adopted on 3 September 1976, along with an Operating Agreement. As defined by the convention, the purpose of Inmarsat was to improve maritime communications, thereby improving communications during distress at sea and increasing sea safety. This convention was also created to improve the management of ships, maritime correspondence services and radio-determination capabilities. Sources state that since its inception, South Africa was party to this convention; however other sources state that this convention was only put into force in South Africa by Telkom in 1994.