If anyone's interested in reading about my experience the first time I went, which was less dramatic, I described what I could remember here: http://divia.posterous.com/my-first-hour-in-the-flotation-ta....
I couldn't sleep, and lasted only about 20 minutes in the chamber. I didn't have hallucinations, but I did start feeling paranoid and the lack of sensation was (for lack of a better word) intense. I couldn't stand it. Perhaps I would have started hallucinating if I had stayed longer. Sensory deprivation is a truly bizarre experience.
A flotation tank is a bit different than what's described in the article - if you move, you feel waves in the water, hear splashes echo, etc.
All of this focusing on hallucinations seems kind of odd. People hallucinate all the time, they just rationalize it as misreading signs and whatnot. Big deal.
* I'm guessing half an hour, but the isolation unsurprisingly made it seem far longer. Isolation without control would be terrifying.
> Among the nine participants who scored high on the first survey, five reported having hallucinations of faces during the sensory deprivation, and six reported seeing other objects or shapes that weren’t there. Four also noted an unusually heightened sense of smell, and two sensed an “evil presence” in the room. Almost all reported that they had “experienced something very special or important” during the experiment.
(A heightened sense of smell, really?)
Dr. Lily inspired the movies "Altered States" and "The Day of the Dolphin."
LSD == Hallucinations
Hallucinations == Good
.: LSD == Good
Now of course I've taken a lot of LSD and all the other stuff I could lay my hands on: But I reject the notion that hallucinating is better than real life. After each hallucination, real life is what you return to, and must deal with.
Here's a really good interview with him:
They were expecting something out of the ordinary therefore they got it.
Doing this, one will often achieve a feeling of elation and altered consciousness.
Then again, the guy who invented these tanks thought that dolphins were talking to him.