Precontinent is a name of a set of projects to build an underwater "village" carried out by Jacques-Yves Cousteau and his team. The aim of these projects was to show that people could live underwater for prolonged periods of time, while being subjected to the harsh environments of the deep sea. The pressure in the village buildings was regulated to that of the surrounding water, so that people could explore the environment around them. This required adjustments of the air mixture supplied to the buildings.
The projects were named Precontinent I, Precontinent II and Precontinent III. Each following project was aimed at increasing the depth at which people continuously lived under water.