Aquabulle
Launched for the first time in March 1978, this underwater shelter suspended in midwater (between 0 and 60 metres) is a mini scientific observatory 2.8 metres high by 2.5 metres in diameter. The Aquabulle, created and experienced by Jacques Rougerie, can accommodate 3 people for a period of several hours and acts as an underwater refuge. A series of Aquabulles were later built and some are still being used by laboratories.
Read more about this topic: Underwater Habitat