FIU took over operations at Aquarius Reef Base in January. The lab sits about 60 feet below the ocean's surface a few miles off Key Largo.
The federal government owns the lab but cut its budget last year, which put the lab at risk for closure until FIU assumed its operations.
Celebrating the completion of the first Aquarius mission under FIU's oversight, university officials said they were working to improve academic and public access to data collected at the world's only undersea research facility. They also hope to increase opportunities for classrooms to connect live with scientists living underwater.
Aquarius allows scientists to live and work underwater for days at a time without coming up for air. It's a 43-foot-long pressurized metal tube about the size of a school bus.
For more than two decades, marine scientists have used the lab as a base to study the effects of ocean acidification and other environmental changes in coral reef and the populations of sea creatures that call it home. It allows researchers to scuba dive up to nine continuous hours a day without needing to return to the surface or decompress.
Astronauts also use Aquarius for training for space missions. Four astronauts took the plunge last week in the lab's first mission under FIU.
NASA officials said the watery environment is similar to a low earth orbit and helps astronauts field test their skills for space expeditions.
Aquarius also helps astronauts experience living in isolated, extreme environments, said Bill Todd, program manager for exploration analogs at the NASA Johnson Space Center.
When the lab's cooling system needed emergency repairs last week, they weren't phased by the interruption, Todd said.
"My two astronauts said to me, 'This is just like space flight. Perfect,'" he said.
Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.