A Florida university professor who now holds the record for the longest time living under water hopes his research will help on a future space mission.
At the weekend, Joseph Dituri set the record by spending his 74th day living in Jules’s Undersea Lodge, situated at the bottom of a 9-metre-deep lagoon in Key Largo, Florida.
It is the longest anyone has spent in such conditions without depressurisation.
He said his 100-square-foot underwater pod is about the same size as a “pretty tight little motor home”.
That is the “same as when we're going to Mars — and that's a 200-day trip,” said Dr Dituri, who first took the plunge on March 1.
Scientists are studying the effects of close-quarters living for future crewed missions to Mars.
“Our astronauts will have to travel in an environment similar to the one I’m in now — the confined area will limit their options for food, how far they can see and how they can exercise,” Dr Dituri said.
“They will experience muscle loss, bone loss and vision problems. This research could help us better prepare our astronauts to ensure they arrive healthy and strong enough to explore the planet.”
Researcher breaks record for longest time living underwater
Dr Dituri's research includes daily experiments in physiology to monitor how the human body responds to long-term exposure to extreme pressure.
The previous record of 73 days, two hours and 34 minutes was set by two Tennessee professors — Bruce Cantrell and Jessica Fain — at the same location in 2014.
But Dr Dituri plans to stay in the lodge until June 9, when he will reach 100 days and complete an underwater mission called Project Neptune 100.
The mission combines medical, ocean and educational outreach and was organised by the Marine Resources Development Foundation, the owner of the habitat.
“The thing that I miss the most about being on the surface is literally the sun,” Dr Dituri said.
“The sun has been a major factor in my life — I usually go to the gym at 5am and then I come back out and watch the sunrise.”
The Associated Press contributed to this report