Continental Shelf Station was an attempt at creating an environment in which people could live and work on the sea floor. Precontinent has been used to describe the set of projects to build an underwater “village” carried out by Jacques-Yves Cousteau and his team in the Mediterranean and the Red Sea between 1961 and 1963. The projects were named Precontinent I, Precontinent II and Precontinent III. Particularly Precontinent II off the sudanese coast received wide public recognition and was documented in a movie with the somewhat sensationalist yet eerie title “World without sun“. For a good overview of the project see: https://www.closed-worlds.com/conshelf-ii-iii or https://www.messynessychic.com/2013/05/27/remains-of-an-underwater-habitat-left-by-1960s-sea-dwellers/
thanks to Lajos Talamonti for the lead!