Underwater exploration has always been characterized by a struggle against nature. From early diving bells to rebreathers, the technology and design advances of man’s undersea endeavors draw an unsurprising parallel to the more popular exploration of space: they are the bizarre, sometimes insane systems of life support that defy nature, sending men where strong forces deem men should not be.

Marking the peak of this journey below sea level are underwater habitats, which have a 50-year history of scientific discoveries, tight living quarters, long decompression times (see sidebar) and insane amounts of risk. And just four habitats have advanced us from dipping our feet tentatively to emerging from a moon pool in a home away from home hundreds of feet at the bottom of the sea. Switch off The Life Aquatic with Steve Zissou and dog-ear Twenty Thousand Leagues Under the Sea. It’s time to study some subaquatic non-fiction.

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Conshelf

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Created under direction from Jacques Cousteau, the Continental Shelf Station program (Conshelf) ran from 1962 to 1965 and was comprised of three separate habitats installed to research the physical and mental effects of sustained underwater habitation and saturation diving. A steel cylinder some 16 feet long and 8 feet in diameter, Conshelf I sat in 30 feet of water near Marseilles, France and was home to two aquanauts for seven days. During their stay, the Aquanauts were able to dive for long periods without the need for decompression time, allowing them to study wildlife and even establish an underwater farm. Outfitted with a radio, TV, library and sleeping quarters, Conshelf I was supported by a surface team of up to 30 people.

Conshelf I proved that prolonged underwater habitation was possible, leading to the 1963 launch of Conshelf II in the Red Sea of Sudan. With a larger starfish-shaped five-man main structure at 30 feet, a second structure placed at 82 feet and a two-man submarine, Conshelf II was a much more advanced installation. Cousteau directed a documentary about the Conshelf II project, called Le Monde Sans Soleil (World Without Sun), which won an Oscar in 1965 for best documentary feature. Some of the project’s funding came from the French oil industry, so Conshelf II’s aquanauts also performed experiments to study the practicality of industrial labor at depth.

In 1965 Conshelf III went deeper, finding a home at a depth of 330 feet in the waters of Nice, France. For three weeks the habitat’s six divers were tasked with maintaining a mock oil structure to research the effectiveness of human labor at such great depths. The spherical Conshelf III structure was roughly 20 feet in diameter and required a surface support crew of over 150 people and a dozen ships. The experiments and tests proved that while such a mission was possible, there was no practical application for the oil industry.

DECOMPRESSION 101

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The longer a diver stays underwater, the more nitrogen from the gas he’s breathing will dissolve into his body tissue. At the end of a dive, he must ascend very slowly to allow these bubbles to dissolve via respiration. Ascending too quickly is like opening a bottle of shaken soda: the bubbles will expand under the decreasing pressure and cause decompression sickness, aka “the bends”. During underwater habitation the principle is the same, but decompression times are much longer (several days) because aquanauts have been at depth for a much longer time. To avoid danger, aquanauts must be very slowly returned to surface pressure in locked pressure chambers before they can again breathe fresh air.

SEALAB

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Not to be outdone by some French filmmaker, the U.S. Navy launched the SEALAB program to research the merits of saturation diving and undersea habitation. SEALAB ran from 1964 to 1969 and included three separate installations, creating a legacy of not just invaluable information about the physiology of saturation diving, but also the birth of the Rolex Sea-Dweller. SEALAB I, a submarine-like 40-foot by 9-foot steel cylinder, was launched in 1964 off of Bermuda and sat in 192 feet of water. Originally planned as a three-week mission, SEALAB I and its four divers completed only eleven days before an approaching tropical storm canceled the balance of the mission.

1965′s SEALAB II hosted ten men at 200 feet in the waters of La Jolla, California. The 50-foot-long structure was 12 feet in diameter and featured amenities like a hot shower, refrigerator and laboratory. Despite Mercury Astronaut Scott Carpenter’s record 28 days aboard, SEALAB II is likely best known for employing Tuffy, a bottlenose dolphin. The Navy hoped that Tuffy would be able to manage deliveries and aid a diver in distress but, perhaps unsurprisingly, Tuffy proved unreliable.

The ambitious SEALAB III and its astounding 600-foot depth proved to be more than the Navy had bargained for. Launched in early 1969 off the coast of San Clemente, California, SEALAB III was originally designed to house teams of nine men for up to 12 days. Shortly after placement, the structure showed signs of a leak, and when repair attempts led to the death of a Navy diver, the SEALAB program was shut down. Despite the failure of SEALAB III, the program as a whole provided the Navy with crucial insights into the methodology of mixed-gas and saturation diving.

Tektite

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The result of a partnership between NASA, the U.S Navy, the U.S Department of the Interior and General Electric, Tektite sought to explore the behavioral effects of tight living in hostile environments and further develop mixed-gas diving techniques. Tektite spanned two successful project generations in the same habitat situated in 43 feet of water along the coast of the US Virgin Islands.

The Tektite habitat was comprised of two vertical cylinders, each 18 feet long and 12.5 feet wide and mounted to a rectangular steel base. 1969′s Tektite I saw a team of four aquanauts, all scientists rather than professional divers, complete a 58-day mission that required 19 hours of decompression before the team returned to life on the surface. Tektite II was the first undersea habitat to host a mission staffed by an all-female crew, consisting of four scientists and one engineer. Behavioral and physiological research for both missions was conducted via video surveillance, and the information aided the Navy and NASA in understanding the effects of long-term crew isolation.

Aquarius

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Currently situated in 65 feet of water on the edge of a reef in Key Largo, Florida, Aquarius functions as a full-time scientific research facility that allows a crew of four scientists and two technicians to run 10-day research missions. Built in 1986, the 43-foot by 9-foot Aquarius was originally deployed in the U.S Virgin Islands and owned by the National Oceanic and Atmospheric Administration (NOAA); after budget cuts in 2013 it was bought by Florida International University. Aquarius has proven an excellent platform for underwater research, enabling scientists to conduct much longer dives than would be possible from the surface.

Designed to weather a hurricane, Aquarius is fitted with four 24-ton legs that offer seven feet of height adjustment. With modern conveniences like internet, phone, hot water and air conditioning, Aquarius has successfully hosted over 114 missions and has even aided in the training of NASA astronauts and Navy divers. When a mission is over, the aquanauts have to complete a 17-hour decompression process during which the ambient pressure in the habitat is slowly lowered to match that of the surface, allowing the divers to exit the facility and swim to the surface without risking the bends. Next month, Aquarius will play host to Fabien Cousteau’s ambitious Mission 31, during which the diving family scion plans to live there for a full month. The dream of living underwater goes on.

ADVENTURE IS ONE CLICK AWAY

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