Key Largo used a sealed underwater habitat 22 feet below the surface to test prolonged human immersion; the result revealed a startling effect as a professor emerged after 100 days with his spine compressed and his height reduced by half an inch

The human body is not as fixed as it looks. Joseph Dituri discovered that after spending 100 days living inside a small underwater habitat off Key Largo, Florida. When he finally returned to the surface in June 2023, he reported that he was about half an inch shorter than when he went down. The change was temporary, but it showed just how much the spine can respond to an unusual environment.

Dituri, a University of South Florida professor and former U.S. Navy diver, entered Jules’ Undersea Lodge on March 1, 2023. The habitat sits beneath the water near Key Largo, where he stayed for 100 days as part of a research project called Project Neptune 100. He continued teaching students remotely while researchers monitored his physical and psychological condition throughout the experiment.