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 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. Tanks of those days would be very
intimidating to the average person. Over the years Lilly continued 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. Today's tanks have water that is only 10 inches deep.
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 the 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 neurologists at 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 float tanks 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, flotation 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.