A university professor resurfaced from underwater on Friday, marking the end of his 100-day stay at a Florida Keys lodge designed for scuba divers, marking the world record for the longest period living underwater without depressurization.

Dr. Joseph Dituri, known as "Dr. Deep Sea," achieved the new record after being submerged 30 feet (9.1 meters) in a Key Largo lagoon, surpassing the previous record set by two Tennessee professors at the same Jules’ Undersea Lodge in 2014, which was 73 days, two hours, and 34 minutes.

"It was never about the record," said Dituri after achieving the milestone. "It was about extending human tolerance for the underwater world and for an isolated, confined, extreme environment."

As a University of South Florida educator with a doctorate in biomedical engineering and a retired US Naval officer, Dituri has a strong background in diving exploration and medical research.

After 74 days underwater, Guinness World Records recognized Dituri as the new record holder on its website.

Ian Koblick, the head of the Marine Resources Development Foundation, which owns the lodge, intends to submit a request to Guinness to certify Dituri's achievement of reaching the 100-day mark.

The initiative, named Project Neptune 100, was organized by the foundation with the aim of studying the effects of prolonged exposure to extreme pressure and isolation on the human body and mind.

Contrary to a submarine, the underwater habitat owned by the foundation intentionally matches the higher pressure of the surrounding water surface instead of maintaining surface pressure.

The information gathered from the experiment could prove valuable for ocean researchers and astronauts during future long-term missions.

Throughout his stay, Dituri conducted daily experiments, collecting data on his body's response to increasing pressure over time. He also engaged with approximately 5,000 students from 12 countries through online meetings and thought a course at the University of South Florida while welcoming over 60 visitors to the lodge.

"The most gratifying part about this is the interaction with almost 5,000 students and having them care about preserving, protecting and rejuvenating our marine environment," Dituri said.

He plans to present the findings from Project Neptune 100 at the World Extreme Medicine Conference in Scotland, scheduled for November this year.