Aquarius Underwater Laboratory

R/V Western Flyer. Image courtesy of Monterey Bay Aquarium Research Institute

Aquarius an undersea laboratory and home for scientists studying the marine environment that is owned and operated by Florida International University (FIU). The underwater habitat currently sits in about 60 feet of water, 4.5 kilometers offshore of Key Largo, Florida, on a sand patch adjacent to deep coral reefs in the Florida Keys National Marine Sanctuary.

Through saturation diving techniques, Aquarius allows scientists to live and work underwater 24 hours per day for mission that typically last 10 days. Living underwater allows scientists to conduct research and observe thing that would be difficult to observe if diving from the surface.

Saturation Diving

An aquanaut working to maintain the outside of Aquarius by cleaning off marine growth

An aquanaut working to maintain the outside of Aquarius by cleaning off marine growth. He is using a hookah rig that includes a typical second stage regulator attached to an air hose that leads to Aquarius and an air storage tank. A secondary "bailout" bottle is on his back for safety if problems develop with the hookah rig. Click image for larger view.

Aquarius scientists escape the limitations of conventional surface-based scuba diving through saturation diving. Instead of coming to the surface after diving, scientists who use Aquarius return directly to the undersea laboratory. As long as aquanauts don't go back to the surface they can use special dive tables to greatly increase their bottom time - to nearly ten times over what they typically have using conventional surface-based diving techniques.

At the end of a mission, aquanauts undergo 15 hours and 45 minutes of decompression, where the pressure inside Aquarius is slowly reduced from ambient (the pressure at the working depth of Aquarius is 2.5 times surface pressure) back to surface pressure. At the end of decompression, Aquanauts exit Aquarius and scuba dive back to the surface.

Being able to live underwater and not return to the surface after each dive saves time and also money for scientists. Bottom time conversions from saturation missions to surface-based programs suggest that it would take at least 60-70 days to match the same bottom time as a ten-day saturation mission. Repetitive deep-diving schedules also expose divers to greater risk of decompression sickness than saturation diving. 

The Aquarius System

Aquarius' life support buoy

Aquarius' life support buoy is 10 meters in diameter and contains compressors, generators, computers, and advanced telemetry and control systems for transmitting real-time video, audio, and data from inside Aquarius to mission control, which is located nine miles away on shore.

The fully equipped underwater laboratory includes several components.  The Aquarius “habitat” module is an 85-ton double-lock pressure vessel that measures approximately 43 feet long and nine feet in diameter. Entry to Aquarius is through the “Wet Porch.” The Entry Lock, sized at 500 cubic feet, contains bench space for computers and experiments, power equipment, life support controls, small viewports, and bathroom facilities. The largest living space in Aquarius is the 1,400-cubic-foot Main Lock, which includes berths for a six-person crew, computer work stations, two large viewports, and kitchen facilities. The main lock also contains life support controls, so both the entry and main locks can be independently pressurized.

The Aquarius baseplate is a 116-ton structure that provides a stable and level support base for the habitat. Each of the four legs contains 25 tons of lead ballast. The legs have seven feet of adjustment for leveling in variable seafloor terrain through the use of hydraulically-driven screw jacks. The habitat and baseplate were designed to survive severe storm conditions and have successfully weathered hurricanes in both the Caribbean and Florida.

The Life Support Buoy (LSB) is a 10-meter diameter buoy that was provided by NOAA's National Data Buoy Center. Maintained above Aquarius on a five-point mooring, the LSB includes a communication tower and over 70-square meters of inside work space. Inside are two diesel-powered 40 kW generators, two air compressors capable of 18.7 cfm (cubic feet per minute) output for filling air flasks, VHF radios, a cell phone, and a microwave broadcasting system. The LSB is linked to Aquarius by a three-inch diameter 42-meter unitized umbilical, which contains hoses that supply air from the compressors and oxygen from storage flasks, power lines from the generators, and cables and wires for data and communications.

A shore-based Mission Control center is located in Key Largo, approximately 12 kilometers from Aquarius, and includes a specially designed "watch desk" with computers and communication equipment linked to Aquarius via wireless telemetry. Also located on shore are docks for the program's boats; office space; storage and work rooms for dive gear and equipment; an electronics shop; a six-person, dual-lock decompression chamber for emergency evacuation of Aquarius; two laboratories; and living accommodations for on-duty staff and visiting scientists.

Aquarius Science Results

Aquarius scientists work to understand our changing ocean and the condition of coral reefs. Unfortunately, coral reefs are threatened worldwide by increasing amounts of pollution, overharvesting of fisheries, disease, and global climate change. Science achievements from Aquarius include discoveries related to the damaging effects of ultraviolet light on coral reefs, geological studies that use fossil reefs to better understand the significance of present-day changes in coral reefs, research on how corals feed, water quality studies that evaluate sources of pollution, and long-term studies of reefs to help distinguish between changes caused by natural system variability and humans (due to pollution and overharvesting).

 

To learn more:

AquariusExternal link, Florida International UniversityExternal link