after spending 31 days living in the Aquarius underseas station.
Cousteau was one of three men to spend the entire mission aboard Aquarius, the others being Mark Hulsbeck and Ryan LaPete. The base is located in the Florida Keys, and sits about 63 feet (19 meters) beneath the ocean. Serving as a base of operations, it provided a safe place for the scientists and researchers to come and go throughout the mission, which was dubbed Mission 31.
The point of the 31-day ocean expedition was to not only further explore the marine life in and around the Keys, but also promote conservation efforts of the ocean as well. Cousteau and his companions spent as much time as possible in their scuba gear, outside of their underwater base, as they studied how well they adapted to living beneath the surface. They returned to the Aquarius for new oxygen tanks, to record their observations and data, and to rest between experiments.
Living under the water allowed the divers to complete more research projects than they would be able to if they started at the surface. One of the researchers who was a part of the project estimated that he was able to collect 6 months worth of data in the 31 days thanks to the fact that they actually stayed under the surface for that time frame. That gives you an idea of how important this mission was, and how valuable the data the collected could be.
Before returning to the surface last Wednesday, the three men had to spend 15 hours and 45 minutes in a decompression chamber. The new 31-day record breaks Cousteau's grandfather's record, set back in 1964, by a single day.