Tektite Habitat: The Pioneering Undersea Laboratory

In the late 1960s and early 1970s, the United States conducted one of the most ambitious experiments in human undersea habitation: Project Tektite. Designed to explore how people live and work beneath the ocean’s surface for long periods, the Tektite habitat became a landmark in oceanographic research, psychological studies, and the development of saturation diving.

An artist rendering of the Tektite habitat showing its inner structure. Credit: NOAA Central Library Historical Fisheries Collection

Origins of Project Tektite

Project Tektite began as a joint effort of the U.S. Navy, the Department of the Interior, and later NASA, at a time when nations were racing not only into space but also into the depths of the sea. Named after tektites—natural glassy objects formed from meteor impacts—the project symbolized exploration in an extreme environment.

The central goal was to determine how scientists could perform extended research underwater and how humans psychologically and physiologically adapted to long-duration confinement under pressure. This knowledge would aid both oceanography and emerging space programs.

Design of the Habitat

The Tektite habitat was installed in Greater Lameshur Bay in the U.S. Virgin Islands in 1969. The location was selected for its generally moderate seasurface swell, warm clear water, and a biologically diverse coral environment. The habitat consisted of two cylindrical living modules 12.5 feet in diameter and 18 feet tall connected by a flexible tunnel. The structure was anchored roughly 40 feet below the surface.

Credit: Wikimedia Commons

Inside, the habitat housed sleeping quarters for several aquanauts, a common living and working area, communications and scientific equipment, life-support systems that maintained pressure, oxygen, humidity, and temperature, and a “wet room” with a moon-pool entrance for divers

The habitat operated as a saturation diving environment, where aquanauts worked and lived under increased pressure which caused their bodies to become saturated with dissolved gases. They could work underwater for extended hours without needing repeated decompression.

Tektite I: A Historic 60-Day Mission

The first major mission, Tektite I, was launched in February 1969. Four civilian scientists—Ed Clifton, Conrad Limbaugh, Richard Waller, and John Van Tyne—lived underwater for a record-setting 60 days. At the time, it was the longest continuous underwater habitation ever attempted.

The team conducted marine biological research, surveyed local reef systems, and tested new diving techniques. Equally important were the observations gathered about team dynamics, psychological stressors, and the effects of confinement—data later compared with astronaut studies.

Diver swimming down to the vessel used during the Tektite II Project. Credit: Wikimedia Commons

Tektite II: The First All-Female Aquanaut Team

In 1970, Tektite II expanded the program with multiple shorter missions focused on scientific research and behavioural studies. Among these missions, the most widely reported was the first all-female aquanaut team, led by marine biologist Dr. Sylvia Earle. The five-woman team spent two weeks underwater conducting ecological surveys and physiological measurements.

This mission attracted significant media attention and helped challenge assumptions about women’s capabilities in demanding scientific environments.

Scientific Contributions

Project Tektite generated valuable findings across several fields. Researchers collected baseline ecological data on coral reefs, fish populations, and benthic communities around the Virgin Islands. The long-term presence underwater allowed methods impossible on short dives.

Researchers also studied the effect of confinement and isolation on human physiology and psychology. The program studied sleep cycles and circadian rhythms, physiology under saturation diving conditions, as well as stress and coping mechanisms.

These insights were later applied to both naval operations and space missions. Lessons from Tektite influenced subsequent undersea labs, including Hydrolab, SEALAB, and later Aquarius.

Credit: OAR/National Undersea Research Program (NURP); National Park Service

When Tektite II ended in 1970, General Electric placed the habitat in storage in Philadelphia. A group of interested parties purchased the habitat from General Electric for $1.00 with the stipulation it would be removed from the GE storage facility. The habitat was trucked across the United States to Fort Mason in San Francisco, where it was placed on display.

By 1980, the habitat was fully restored and certified to be used underwater, and named Tektite III; however, funds for actually submerging and operating the habitat again were not available. While the habitat was on display at Fort Mason, many school children were taken through the habitat free of charge by volunteers. Lack of funds ended the project and the habitat was moved to storage along the Oakland Estuary in 1984. After several years, the habitat again deteriorated. In 1991, the habitat was dismantled by welding school students and the metal was recycled.

Though Project Tektite ended in 1970, it remains a milestone in human undersea habitation. It demonstrated that scientists could live and work underwater for extended periods, advanced the technology of undersea laboratories, and contributed foundational data for future long-duration missions in extreme environments.

Tektite also played a symbolic role in the scientific culture of the late 20th century: just as astronauts explored space, aquanauts proved that the oceans—Earth’s inner frontier—could be inhabited and studied with similar ambition.

Credit: OAR/National Undersea Research Program (NURP); National Park Service