There are branches in Aberdeen (Scotland), Houston (USA), Rio de Janeiro (Brazil), Newcastle (England), Perth (Australia), London (England), Melbourne (Australia), Kuala Lumpur (Malaysia), Singapore, Norway (Bergen), China (Beijing) West Africa (Nigeria), the Middle East (UAE) and new branches in early stages of development in St John's Newfoundland & the Eastern Mediterranean to be based in Cyprus.
Membership is open to individuals, companies, and institutions with a genuine interest in the broad field of underwater technology.
SUT promotes the further understanding of the underwater environment and encourages, for example: SUT covers all aspects of technology applied to diving technology and physiology, submersible design and operation, naval architecture, underwater acoustics, subsea systems, geology, geophysics, marine resource exploitation, oceanography, environmental studies, pollution and marine biology.
This precursor society had been set up to facilitate the "interchange of information between users and suppliers of [undersea] equipment".
SUT was modernised throughout the period of Ian Gallett & Bob Allwood's leadership, emerging as a modern, international marine Learned Society with updated statutes and structure by 2015.
The Engineering Committee on Oceanic Resources, based in Halifax, Nova Scotia, became a partner of SUT in 2013.
In April 2017 Stephen Hall, former vice-chair of the Intergovernmental Oceanographic Commission of UNESCO became the Chief Executive on Bob Allwood's retirement, and served until December 2020.