Touted as the only such underwater lab in the world, the Aquarius Reef Base has drawn researchers for two decades because of the ability to work underwater for up to nine hours a day without a threat of getting decompression sickness, or the bends, compared to one hour if they were diving from the surface.
The base got a new lease on life in January 2013 when Florida International University in Miami stepped up with a plan to take over the underwater module when the National Oceanic and Atmospheric Administration (NOAA) announced it was going to decommission the underwater lab it deployed in 1993. The stationary 82-ton FIU Aquarius module sits in the National Marine Sanctuary some five miles offshore of Snake Creek in about 60 feet of water at the base of a coral reef wall. A 200-foot umbilical cord connects it to the surface and provides critical life sustaining services such as electricity, water, computer access and telephones.
"They have everything they need to live comfortably," said Aileen Soto, spokeswoman for the Marine Education and Research Initiative (MERI) and FIU. "It is 46 feet long and 10 feet wide and is the size of a yellow school bus. It even has hot water, Wi-Fi and cots for six people to sleep in."
NASA is currently training four astronauts for missions to space, and most recently, Fabien Cousteau, grandson of famous aquanaut Jacques Yves Cousteau, set a world record when he stayed 31 days at the Aquarius during Mission 31.
Students from the university also get to use it for underwater classroom learning.
"At Aquarius, you can do research that can't be done anywhere else in the world," FIU doctoral student and a coral reef mission scientist Andrew Shantz wrote in a brochure for the college. "You can really start to look at things with 24/7 data. In my research on coral reefs, Aquarius provides all these additional tools and resources that take the work to a whole new level. It's phenomenal."
The 400-square foot liveaboard habitat allows scientists and aquanauts to stay in it while they are conducting crucial research in areas including water quality, coral reef biology, ecology and physiology, long-term ocean monitoring, restoration science, ocean acidification and global climate change.
The module is divided into four areas: a wet porch with the diving gear, which is contiguous with the ocean; the entry lock where the equipment and computers are kept; the main lock, which is the main living area, complete with a refrigerator and galley for cooking; and the bunk room with three tiers of bunk beds.
"It is pretty close quarters," astronaut Mike Gerhardt said. He spent two missions at the reef base.
It is also a perfect environment to test out tools that can be used in space, said Bill Todd, NEEMO 18 project manager with NASA. NEEMO 18 aquanauts are testing a drill that will be used to bore into an asteroid in the future.
"It is world training in the harshest of places," Todd said. "It simulates what it is like in space."
Safety of those using the facility is of the utmost importance, Soto said. There are airtight doors and safety exits with ways to get out in case of an emergency. All activities are monitored 24 hours a day at a mission control center in the FIU building near Mile Marker 83. Several telephones allow those staying underwater to communicate with people on site.
There is also a hyperbolic chamber in case divers experience decompression sickness while underwater. A boat has the ability to ferry up to three divers to the FIU site in a minichamber and then transfer them to the larger facility for medical treatment, Soto said.
Nitrogen from a diver's air tank increases in pressure as a diver descends. For every 33 feet in ocean water, the pressure due to nitrogen goes up another 11.6 pounds per square inch. As the pressure increases, more nitrogen dissolves into the tissues and builds up over time. The underlying cause of symptoms in the body during bends is due mainly to nitrogen bubbles being released and blocking blood flow, and disrupting blood vessels and nerves by stretching or tearing them.
The opportunity to use Aquarius is not available to everyone, but those who do use it must pay a day rate as well as meet physical requirements and complete a week of training prior to the 45-minute dive to get to the base.
"There are physical exams and rigorous screening the divers need to go through," Soto said, "and there is classroom training conducted before each mission and diving sessions in shallow and deep water."
For Gerhardt, who has been in space four times -- at the ISS during mission STS-104 and a participant for NEEMO 1 and NEEMO 8 -- the Aquarius offers a one of a kind experience.
Although it is smaller than the space station and doesn't have views of Earth floating by, it has its own charm, he said.
"It's fabulous living underwater. You eat meals and watch fish swim past the portholes."