Folks who have spent time in a flotation tank report that their first experience consisted mainly of figuring out just how the heck to use a flotation tank. Having now had two one-hour sessions in a flotation tank myself, I can confirm that this is accurate.
Flotation tanks, also known as isolation tanks, and occasionally as sensory deprivation tanks, are these days large horizontal enclosed tubs filled with a few inches of water containing a very high concentration of dissolved epsom salts (magnesium sulfate). The resulting solution is so dense that you can’t help but float when you lie down in it. The solution in the flotation tank is heated to body temperature, sanitized, and continuously filtered. The solution does not taste salty; it tastes vile (take my word on this).
Flotation therapy is used for a variety of purposes ranging from relaxation, meditation, or (if you’re like me) because you’ve seen the movie Altered States or the television show Fringe. I am happy to report that I neither regressed to a neanderthal, nor did I emerge from the tank in a parallel universe. As far as I can tell, anyway. I did warn Mrs. Overclock ahead of time that she might get a phone call in the event I woke up naked in the Denver zoo.
March: The First Session
For my first session, I attended a local spa called A New Spirit. Yeah, I know. It was full of New Age music, gently falling water, and the smell of incense, just as you might imagine. Being an engineer, I would have been happier if it had been all stainless steel and the employees wore lab coats and carried clipboards. But what really surprised me was that it wasn’t until I completed my session and was ready to leave that I saw a woman who wasn’t an employee; up until then, all of the customers I saw sitting around wearing the terry cloth robes provided by the spa were men, some of whom were waiting their turn in one of the three flotation tanks.
Each tank was in a private room. I showered in one of the two bathrooms to remove surface dirt and oil from my skin. I stored all of my personal effects in the provided tote bag, put on the bath robe, entered the tank room that had been assigned to me, and closed the door. I hung up my robe, inserted the disposable foam earplugs provided by the spa, and, naked as the day I was born (but a lot fatter and hairier), I opened the hatch at the front of the tank and climbed in.
All three of the flotation tanks at this spa were of similar size, but this one had a hinged hatch at one end, while the other two tanks (which I peeked at when they weren’t being used) had sliding hatches in their mid-sections. The tank appeared to be fiberglass, in top and bottom halves. The bottom half had a water tight liner in it. Both the solution and the air inside the tank were heated to body temperature. I knelt down into the solution, closed the hatch, and laid down.
I spent the next hour trying, mostly unsuccessfully, to relax. At first I couldn’t see or hear anything. But gradually I became dimly aware of the New Age music, which didn’t seem that loud even outside of the tank room, but managed to permeate both the ear plugs and my tinnitus. Eventually the music became dominated by the sound of my pulse in my ears, and, after a bit, the noise of water trickling past the earplug in my left ear. This latter sound came to seem as loud as the rushing torrent of a stream in the mountains in the spring.
As my eyes became adjusted to the dark, I because aware of a ring of light around the seam between the top and bottom halves of the tank. That’s kind of remarkable, since the tank room itself was very dimly lit. But unless I turned my head to either side, I couldn’t really see this band of light, nor did it illuminate the interior of the tank enough to actually make out any detail.
I went through the (apparently common) issue of where to put my arms: down at my sides, up above my head, somewhere in between. I felt compelled to explore my surroundings. I’m of average height and I found that if I stretched my legs down and my arms up above my head, I could just barely touch the far ends of the tank. The tank was proportionately narrower, so that I could touch either side without extending my arms very much at all. As I tried to relax and float, I drifted around in the tank, occasionally bumping into the sides.
The spa provided one of those foam "swim noodle" tubular pool toys to use as a sort of pillow, and I had to experiment with that as well: use it, don’t use it, put it under my neck, beneath my head, etc. The spa web site mentioned that some people find sitting up in the tank more comfortable. I tried that, only to discover that the heating elements for the water were below the floor, making my bum uncomfortably warm. Being an old guy, my arms and legs would stiffen up and become uncomfortable, so I had to flex them from time to time, which caused the water to slosh around, which caused me to repeatedly bump into the sides of the tank.
After a loooooooooong subjective period of time, an attendant entered the room, knocked on the outside of the tank to let me know my hour was up, and then left. (They ask that you knock back so that they know you aren’t asleep, or dead, or in a parallel universe, and I did that.) I got out of the tank, dried off, and put my robe on. I left the room, took another shower to wash the epsom salts off, got dressed, paid, and left.
First impression: it was interesting. But I spent most of my hour flailing around. I really needed to try it again.
April: The Second Session
I changed a few things for my second flotation session at A New Spirit. I bought some disposable silicon swimmer’s earplugs that I hoped would do a better job of keeping the solution out of my ears. (They did, but didn’t do any better in blocking out the New Age music.) I took a shower before I left the house to save a little time at the spa. Other than that, this visit started out much the same as the first one. I was even assigned the same tank room.
But this time I spent less time figuring out what to do and just tried to relax. I did better this time. I still had to flex my stiffened arms and legs occasionally. I found that I was the most comfortable with my arms in a “hands up, don’t shoot” posture, below the foam float that I still used behind my head, and sometimes with my hands lightly clasped. I was able to concentrate more on my breathing and less on my no longer so strange environment. I had less tension in my neck and back. All things considered, the second session went a lot better. I had some quality thinking time.
What did I think about? Being a typical male, sex, every few minutes. Sometimes with Blair Brown. But mostly I thought about socket multiplexing.
I’ve been working on some open source Linux/GNU-based socket handling code based on work I did under SunOS way back around 1989. (This is part of my Diminuto C-based library you can find on GitHub.) I had wanted to do some refactoring of the socket multiplexing unit test, which is a simple running example of a single-threaded service provider. I worked out all the details while in the tank. Once I got back to my office at home, I completed what I had originally estimated to be a day’s work in a couple of hours. I also fit in lunch at the local deli on my way home from the spa, and a trip to the gym late in the afternoon to lift weights. I call that a good day.
I’m going to keep up monthly sessions in the flotation tanks at A New Spirit for a while. It’s part of my effort to learn to relax, to try to reduce my addiction to constant mental stimulation, to increase my attention span, and improve my ability to get into the zone. I’m also going to work on learning to meditate. All of this in an effort to think deeper thoughts, to gain better insights, and to enhance my ability to think longer term, by at least temporarily removing the more or less trivial distractions that are ubiquitous in today's world.
Or maybe I just like lying around buck naked.