For more than four millennia man has worked under the sea employing a variety of diving techniques and devices. Always the wish was for more depth and bottom time for greater productivity at the work site.
In the early 1960s, the development of saturation diving made it possible to put divers on the seafloor for prolonged periods. Once under full-depth pressure, divers could live and work on the seafloor without frequent, long decompression procedures. There would be one decompression period at the end of the work mission; bottom time could be measured in days rather than hours. Concomitant with greater endurance was increased depth capability. Divers now could work at depths exceeding that of many military submarines.
Three research groups led pioneering work that developed these capabilities: the U.S. Navy's Dr. George Bond, American inventor Edwin Link, and Jacques Cousteau. From 1962 to 1964, their work in diving physiology, deep technology, and operational techniques launched the world's first "aquanauts," people who could live and work on the seafloor for long periods.
The Navy's Sea Lab I, II, and III programs (1964-69) were perhaps the best known. Regrettably, a fatal accident before Sea Lab III became operational resulted in the Navy terminating this line of development. Work continued on operational saturation diving systems, but there would be no more habitats. Ed Link's privately funded "Man-in-the-Sea" program continued to push depth limits and time under pressure. His work was completed by the end of the 1960s. In France, Cousteau developed three Conshelf habitat programs, with his work reported to the world by way of extensive media coverage as well as his magazine, book, and film work.
To live and work in situ required development of underwater houses, or habitats. These little houses under the sea provided an ambient-pressure dry environment with living quarters, research spaces, and dive platforms for work excursions outside. While early habitats were far from comfortable, they provided basic requirements to sustain life for as long as a month. From 1967 to the present, 67 habitat systems have been developed, tested, and put into service worldwide. The United States and Soviet Union had about 15 habitats each. Today, there is only one operational.
For nearly three decades, the National Undersea Research Program (NURP) of the National Oceanic and Atmospheric Administration (NOAA) has supported the world's most active habitat program. Its sponsored projects have included scientific missions with Hydrolab and La Chalupa habitats as well as the German Helgoland II system. Hydrolab operated for nearly 15 years at St. Thomas in the U.S. Virgin Islands and off Florida. La Chalupa worked in Puerto Rico.
In 1982, NOAA funded a new, larger seafloor laboratory. This became Aquarius. It began operations at St. Thomas in 1986, replacing the elderly Hydrolab facility. In 1993, it was moved to the Florida Keys and put under the management of the University of North Carolina at Wilmington (UNCW). This is the only habitat program still operating in the world.
Aquarius is located at a depth of 65 feet on Conch Reef, nine miles south of Key Largo. There are eight ten-day missions a year, each having a team of four scientists and two support technicians from UNCW. As more scientists use the facility and publish their results, the demand to use it has increased. More than 200 scientists already have been involved with this habitat. Even NASA astronauts in training for the International Space Station have had missions here that simulate space work.
If Aquarius is so successful, then why is there only one seafloor laboratory in operation worldwide? There are several answers. First, most early habitats were proof-of-concept experiments intended for single-mission requirements. Once testing and experiments were finished, most were retired. Second, commercial users (e.g., offshore oil and gas developers) need mobile habitat systems, not fixed ones. So the basic saturation diving technique has moved into habitats placed on ships. Finally, there has been a natural reluctance by ocean scientists to adopt this unknown research platform. Few have had any diving experience, so the idea of a seafloor habitat has not been particularly attractive.
Many scientists also find that the fixed-site nature of seafloor habitats limits research opportunities to a specific place. For this reason there is increasing interest in developing mobile one-atmosphere habitats. Essentially small submarines, these platforms, powered by fuel cells or nuclear power, could be capable of both long duration and greater depth. Submarines for pure science still are many years away, but this type of habitat could provide scientific capabilities that do not exist today.