The first floatation tank was developed in 1950 by the American neurophysiologist Professor Dr. John C. Lilly while working at the National Institutes of mental health (NIMH) in Bethesda, Maryland. Together with his associate Dr. Jay Shirley, Dr. Lilly became intrigued by became intrigued by the question of the origins of conscious activity within the brain. The question was whether the brain needed external stimuli to keep its conscious state going. Lilly and his associate set to work trying to devise a system that would restrict environmental stimulation as much as was practical and feasible. Lilly's first tank was one in which the floater was suspended upright, entirely underwater, head completely covered by an underwater breathing apparatus and mask. Over the years Lilly contained his experiments with floatation, simplifying and improving the general design of the tank. Dr. Lilly found that he could float in a more relaxing supine position, rather than suspended feet downward in fresh water, if more buoyant salt was used. Other refinements such as water heaters with thermostats sensitive enough to keep the water at perfect temperature, and air pump to keep the air in the tank fresh, and a water filter for the reuse of he Epsom salts were added over the years. By the early 1970s, Lilly had perfected the floatation tank in much the design used today.

The Floatation tank which the neurophysiologist Dr. Lilly designed has not only been used by neurologist as university medical faculties. scientists in other fields of research have shown increasing interest in the floatation tank and its effects on the human body and mind. In 1982, International REST Investigators Society (IRIS) was founded in order to give the increased number of REST researchers a platform to share their research findings.

For several years were solely used by researchers in university laboratories or by private individuals. In 1983, floating increased in popularity as more became known about it's effects. Today, floatation tanks can be found in health spas, hospitals, fitness centers, professional sport centers, bio-fitness institutes, and are used for "Super learning" courses by universities.