This brings back memories. I tried the tank back in the 80's about a half dozen times. There was a place I'd go to where you could rent a tank for an hour or so.
My experience was similar to yours. Nothing special went on that I could remember. It was sort of nice lying there, but hard to really let go. The tank was devised by John C. Lilly, M.D., who wrote a number of books relating to his work in the area of human consciousness, and his later work in human-dolphin communication.
Looking back, I can say that in my opinion the tank isn't necessary. The mind-awake/body-asleep state and consciousness exploration can be achieved without the tank, although certain binaural cds can provide a nice assist, if you want.
Very best,
I can't believe nobody else has experimented with sensory deprivation for altering consciousness!
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Does anyone have experience with these? Share you experiences. I've floated about a dozen times, nothing special has happened- I usually either fall asleep or am too distracted by thoughts to enter a trance or hallucinate. I was in for 1 1/2 hours each time. I just couldn't get into the theta reverie/hypnagogic state.