Diving History: Jacques Cousteau’s Conshelf Missions

The Conshelf missions paved the way for an era of underwater habitats and research stations; today, the last remaining one is the Aquarius Reef Base, located in the Florida Keys National Marine Sanctuary.

When it comes to diving history, few figures are as recognizable as Jacques Cousteau. Perhaps most famous as the co-inventor of the Aqua-lung and for inspiring a generation of recreational scuba divers, Cousteau was also behind the first populated underwater habitats. Throughout the 1960s, the Cousteau team constructed three consecutive Continental Shelf Stations, known colloquially as Conshelf I, II and III. The impetus for the Conshelf missions was the possibility of using such undersea habitats as bases for mining and drilling operations in the future, and as such, the projects were largely funded by the French petrochemical industry. Designed as a series of underwater living and research facilities, the three stations were originally intended to be part of a 5-station project that would take a decade to complete, and would reach a maximum depth of 1,000 feet (300 meters). However, as Cousteau became increasingly concerned throughout the 1960s with marine conservation, rather than exploiting the sea’s resources, the purpose of the stations was diverted and only three were completed, attaining a maximum depth of 330 feet (100 meters). 

Conshelf I was constructed in 1962, in 33 feet (10 m) of water off the coast of Marseilles, France. The habitat, also known as Diogenes after the Greek philosopher, was a watertight steel cylinder that measured 16 feet (5 m) long and 8 feet (2.5 m) in diameter. The following year, oceanauts Albert Falco and Claude Wesly became the first to spend a week beneath the surface of the sea, during which time they made basic observations of the marine life surrounding the underwater habitat. Each day, the two men spent a minimum of five hours exploring outside the habitat, and even spent time cultivating a sea farm. Between these endeavors, the two men were subjected to daily medical exams, which measured the physiological effects of living at depth. Although Conshelf I was small, it was equipped with a series of comforts including a television, radio, library and a bed. Neither Falco nor Wesly seemed to suffer any ill effect from their week underwater, and as such the first Conshelf mission was deemed a success. In 1963, the Cousteau team stepped up their ambitions and began work on Conshelf II. 

Located in the Sudanese Red Sea, Conshelf II was considerably more advanced than its predecessor. In addition to the starfish-shaped living habitat submerged at a depth of 33 feet, Conshelf II included a deeper habitat at 100 feet (33 m) and a submarine hangar, which held the team’s “diving saucer,” a 2-man submarine. This time, five oceanauts took up residence in the main habitat for 30 days, during which time two of them spent a week in the deeper habitat. During this mission, they would become amongst the first to breathe helium mixed with oxygen in an attempt to avoid nitrogen narcosis at depth, thereby demonstrating one of the earliest examples of saturation diving. The team had extensive surface support, which provided the habitat with air, water, food and power. Experiments conducted during the Conshelf II mission made considerable inroads into understanding the physiological effects of diving and pressure, and were recorded in Cousteau’s Academy Award-winning 1964 documentary, World Without Sun. In describing the adventures of the Conshelf II oceanauts, the documentary sparked a global interest both in marine conservation and recreational scuba diving. 

The third and final Conshelf mission was perhaps the most ambitious of all, and saw six oceanauts descend to a habitat submerged in over 330 feet of water (100 m). Conshelf III was located in the Mediterranean Sea, between Nice and Monaco, and the oceanauts spent three weeks there performing industrial tasks on a mock oilrig. Although this mission too was deemed successful, it also signaled the end of the Conshelf missions, and of Cousteau’s support for marine exploitation. Although the missions proved that humans were capable of living and working underwater, further advances in technology mean that these days, many underwater industrial tasks are carried out by robotic devices rather than by people. 

The Conshelf missions paved the way for an era of underwater habitats and research stations; today, the last remaining one is the Aquarius Reef Base, located in the Florida Keys National Marine Sanctuary. Last year, in a fitting salute to the revolutionary work of his grandfather, Fabien Cousteau led a team on a 31-day expedition to Aquarius, during which time they collected enough data for 10 scientific papers. 

Fabien Cousteau’s Aquarius expedition, dubbed Mission 31, illustrates how times have changed since his grandfather’s Conshelf missions. Instead of investigating how to exploit marine resources, Mission 31 was dedicated to studying the effects of climate change and pollution upon the marine environment. This shift in our perception of the oceans began with Jacques Cousteau in the 1960s, and it’s this legacy for which the Conshelf missions should be remembered.