Sensory Deprivation Tank

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 Field Report #2: Sensory Deprivation Tank

(Meditation: reports from the field are part of an ongoing series)


Not knowing how near Truth is,

People seek it far away – what a pity!

They are like he who, in the midst of water,

Cries in thirst so imploringly. 

Hakuin Ekaku, Zen Master


sense_tank1Tonight was my first time in a sensory deprivation tank. Some friends of mine here in Vancouver recently purchased one and have opened it up to the public. Knowing I like to meditate they offered me a free trial run and I happily obliged. As it turned out, it was like a marriage between deep meditation and SCUBA diving at night. Both are experiences of vast expanse and boundary-less awareness; both keep you coming back for more.

For those who don’t know, a sensory deprivation tank is a chamber half-filled with a mix of water and Epsom salt (a lot of Epsom salt). Inside the chamber it’s completely black and essentially sound proof. So when you lie down in the tank you float effortlessly, and can’t see or hear a thing from the outside. The water is heated to 93.5 degrees, the temperature of the human body, so you can’t really feel the water unless you slosh around. The combined effect is a sensory deprived, suspended limbo.

When I arrived at my friend’s house he had the water filtered and the tank ready to go (he’s only had the thing for a couple of weeks and already has several paying customers per day). I showered down, hopped naked into the tank, and shut the door behind me.

The chamber was completely black. Lying back in water I was happy for the recommendations from my girlfriend not to shave before I came. The water was very salty and even without any knicks or cuts from a razor other orifices burned upon entry. That sensation passed and I was surprised by how easily my head rested in the water while my body floated, only partly submerged. It was a bit like a waterbed – without the cover. The disturbed water gradually stopped rippling around me until all that remained was the darkness and my breath.

SCUBA1The experience of complete blackness and spatial disorientation was not entirely new to me. As a former SCUBA dive instructor I used to go night diving with friends off the coast of Vancouver.  While descending along underwater cliffs 20 meters down, we’d turn to face out to sea, shut off our lights, and rest suspended in the black abyss. From here it’s completely black, you can’t see anything and have absolutely no reference point to where you are. You’re also under 60ft of water so you’re pressurized equally at every point on your body (so you can’t feel gravity’s pull). The effect is complete disorientation and you have no idea of what’s up or down, or even how deep you are. It’s just you, alone, suspended in the vast black nothingness of the Pacific Ocean. It was actually pretty freaky (not to mention dangerous) and we’d usually turn the lights back on after just a few seconds of darkness.

Back inside the sensory deprivation chamber I settled into the water and was able to get comfortable pretty quickly. There was no fear of impending shark attacks and it was pleasantly warm and quiet.

I closed my eyes and began meditating as I normally would. I remained still, relaxed, and paid attention to my experience. After several minutes the thought struck me to open my eyes. To my surprise, nothing in my experience changed. I felt my eyelids opening, but there was nothing to see. They opened into the same blackness they were closed behind only moments before. This was an interesting experience and it made me feel as though I was looking out into endless space. Having absolutely no visual reference to where I was I couldn’t help contemplate the true vastness of the universe all around me. Normally the vastness is constrained by the walls around us, or the horizon line in the distance, but not in the darkness. Here it remains limitless and yours to consider.blackspace

This is when I noticed another interesting aspect of my experience. Although I couldn’t see anything, I observed the mind habitually creating images and outlines of where it “knew” my body and surroundings were. By this point my legs didn’t really have any sensation, as they’d become accustomed to the temperature of the still water around them. Yet my mind kept returning to a “visual” image of where my legs were and it groped and searched for some experience to locate them. While I resisted moving so as not to ripple the water and reveal their location, I imagined that this might be the experience that amputees have of missing limbs.

It was a strange phenomenon to observe the mind groping around habitually for some sort of reference, and then, when it couldn’t locate one, to just imagine it instead. It was like the mind needed an anchor otherwise it might melt away into the blackness. In fact, this is exactly what began to occur as I continued meditation and the mind relaxed of its own accord. At several points during the session I experienced no boundary or distinction between my mind, my body, and the water around me. My sense of awareness was no longer locked in my head, behind the eyes. It was an experience of awareness without boundaries.

brick_wallFollowing these brief episodes, the mind would clamour back into gear and this is when I really noticed its habitual need for constrained boundaries and points of reference. It couldn’t really operate in a realm without limits. In fact, it actually created its own imaginary confines when it couldn’t feel any physically. I didn’t try to do it; the mind did it automatically: boundaries just kind of popped into every thought I had. It was very strange to observe.

It seems the mind can only operate in relationship to other things. This makes sense, I guess, because our egos apparently evolved as a way for us to differentiate ourselves from our environment. Without this feature of the mind we wouldn’t have the feeling of being an individual, there’d be no ‘others’ or world ‘out there’. So as the sensory boundaries of my experience fell away it's not surprising that the mind would keep trying to do its thing, defining boundaries even where there were none. This constant self-referencing in relation to other things is an impulse that’s powered by several thousand years of evolutionary habit! It doesn’t want stop, even in a sensory deprivation tank.

alexgrey_oversoulBut it does stop during meditation. That was my brief experience anyway. As I described earlier, there were moments when something much more significant began to seep-in through the gaps between my thoughts. As my mind relaxed, eventually it was drowned out altogether. What was left was vast and boundary-less, with qualities that were free from the compulsive grasping that characterizes the mind. In a flash I realized that it was this undifferentiated state that was actually the baseline of all experience. And in fact it was this very state that the mind was so compulsively fighting against as it obsessed to create barriers/distinctions/'others’ in any way it could. I found this quote tonight by Ken Wilber that describes it well:

“We perceive all sorts of objects as if they were separate from us. And we resist, we actually fight, the awareness of unity with all these perceived objects… We fight, in short, unity consciousness. Thus we are brought back to our major point: through assuming appropriate spiritual practices, we start to learn just how we resist unity consciousness. Spiritual practice forces this fundamental resistance to surface in our awareness… To see our resistance to unity consciousness is to be able, for the first time, to deal with it and finally to drop it – thus removing the secret obstacle to our own liberation” (1).

Slipping in and out of this experience, I heard three knocks on the door of the chamber that signaled my hour was up. I climbed out of the tank, showered, and said good-bye to my friend.

When I got outside I realized I was experiencing a sort of reverse sensory shock. I was disoriented again, but this time in a different way. Now I was trying to get a grip on the physical world around me. Where the heck did I park my car? It’s hard to say if this was the result of the sensory deprivation or the meditation, but it faded after about 10mins.ocean1

All in all, it was a surprising experience to see the mind’s habitual need to always be in reference to something else. Ultimately, however, this mental groping for the safety of certainty was no match for what still lays beyond it. The vastness I felt as the false boundaries of the mind fell away was like night diving in my own consciousness: floating in a suspended sea of awareness, without any notion of up or down, left or right, just the pregnant expanse of directionless infinity.


(1) Wilber, Ken (2001). No Boundary. Boston: Shambhala Publications, p 134.



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  • Comment Link OV Saturday, 14 May 2011 03:09 posted by OV

    Greetings Bergen. My one and only time in a SDT was in Calgary in 1989, and it sounds like your tank was a lot better than the one I used. Mine was a commercial operation that wasn't quite 100% on the darkness and silence. After about ten minutes or so I could detect a faint outline of where the door was, and every once in awhile I could hear outside noise faintly. I came to the conclusion that the deprivation needed to be total and this wasn't too much different than I could get at home in my windowless bathroom. Well, except at home the temperature declines and you can't help but make contact with the tub once in awhile which ruins the whole experience.

    I'd first heard of the tank in John Lilly's book "Center of the Cyclone". "Altered States" was a movie based on this with William Hurt making his movie debut; good movie, have you seen it? I wasn't on psychedelics when I was in the tank but I'd still be curious to try this for the duration of the trip, 5 to 8 hrs.

    I think with the mind altering procedures duration and endurance is a very big part of the experience. If a person can hang in there until their second wind kicks in then after 72 hrs of sleep deprivation strange things start to happen. This duration is common in the mystery schools, and in some of the old mythology. I wonder if you were in a tank for 72 hrs if you could tell if you fell asleep or not. If you were being monitored with EGG, I wonder if they could tell the difference between sleep and deep meditation.

    Last year I heard a story about ancient Egyptian mystery initiations, and I don't know if it is true but I'll pass it along. Along the Nile there are archaeological sites that supposedly were used for initiation ceremonies. The first as close to the head of the Nile, forget the name, but if you wanted to join the mystery school you had to enter in one door and come out the other, if you returned out the same door you came in you didn't get a second chance. As you entered the first door you discovered that it was the only door in a room with a pool full of large crocodiles. We can see today without the water that at the bottom of the pool there was a tunnel that led to a pool in the adjacent room which held the exit door. The underwater tunnel was big enough for a human but too small for a crocodile. Needless to say the initiate was not told about the tunnel, so diving into the pool took an enormous leap of faith, but they knew there were crocodiles because this is what happened to all those that didn't exit from either door, and the way out had to be through the pool because there was no other way. Can you imagine the intensity of this experience?

    There were seven of these sites, corresponding to the chakras and the 6th or 7th was the great pyramid at Giza. I've been in the King's chamber myself and there is an awesome feeling about it, but there were guides along and no way to stay overnight. It would have been totally dark and totally quiet. Supposedly at this stage the person is put inside the sarcophagus, the lid put on, and left for 72 hrs with no way of knowing if anybody would ever come back for them. Supposedly after 72 hrs of total sensory deprivation you are capable of rewiring your brain. I assume that the previous six initiations, plus schooling etc enables the rewiring such that one is coherent at the end. I don't know, but that is one story about the 72 hrs.

    A couple of weeks ago there was a Hathor message about transitional states of consciousness and the associated void point when one moves from one reality to another. I wonder if 72 hrs in a tank would create this void point without having to wait around for crisis or trauma. The link to that message is below and I think it contains good information.


  • Comment Link Bergen Vermette Wednesday, 18 May 2011 05:28 posted by Bergen Vermette

    Hi, OV. Very cool picture you paint of the Egyptians. Whether of not it's true, I was definitely reminded of Indiana Jones!

    As for the 72 hours brain rewiring, like you, I really have no clue. If by 'rewiring' we're talking about upsetting habitual patterns of thought and perception, I guess that'd make some sense. Meditation seems to do the same thing; so a long period of sensory deprived meditation would probably have a significant effect if one applied him/herself to it.

    That said, I'm a bit leery of these kinds of claims (like 'brain rewiring'). I mean, what does that even mean? If we throw them around too much, without being specific or backing things up with evidence, we risk slipping into the realm of New Age woo-woo (not where I think you're going, by the way).

    I'm interested in cataloging experiences of meditation in a clear and verifiable way. Verifying subjective experience is difficult but I think it's possible. That's why I try to stick with descriptions of insights or illuminations, rather than, say, energetic experiences or visions of God. The latter are slightly more interpretive and easier to discount. Insights, however, seem to carry a certain undeniable weight to them. (although I suppose the readers can be the judge of that).

    And by the way (shameless plug alert) I know that you live in Vancouver, so if you'd like to give the Tank another shot checkout my friend's place in North Van: Thanks for the comment and see you again soon.

  • Comment Link OV Friday, 20 May 2011 03:59 posted by OV

    Thanks for replying Bergen. I read through your article again with the primary focus being on the meditation aspects, and thought it would be worth some time to explore that on my own. I only started meditating, a centering prayer practice as taught by Father Keating, for about three years now. It started with once a week in a group circle but not much outside of that. A couple of years ago I went on a week long silent retreat lead by Cynthia Bourgeault where we would do three sets of twenty minute sitz a day, and this was the first time that I felt that something was "happening" other than simply waiting for the time to expire. I'm currently in the 311th consecutive day of meditating two hours a day; I've found that keeping track of the days is a big incentive since a missed day means you have to start the count over at day one. This Easter I chanted the Psalms following each one with a 15 minute sit; I started at 9:00 am Thursday and with a few breaks, and a full seven hours sleep on Friday night was able to get through all 150 of them in time for the Easter Sunday morning service. I was hoping for an emotional high but it felt like jet lag.

    I still cannot say what specifics benefits I've received from meditation, though I seem less high strung than I used to be and I don't hamster wheel a grievance near to the same extent. During meditation I find it getting easier to shut down the monkey mind chatter, and longer sits are no longer a physical ordeal. I don't have insights, or observations, since the goal with centering prayer is to stop the monologue as soon as you notice it. I think the main reason I keep doing it is to see what happens if a person does it long enough.

    "Rewiring the brain" as a tangent that might not fit with this discussion, it might be the purpose of meditation. One of the books I'm reading now is Daniel Goldman's "Emotional Intelligence" and I got the impression that the physical brain can and does change the way it is configured and this affects behavior. It can happen very quickly, as in an incident that caused Post Traumatic Stress, or it can take a long time to recover from this. It's more than habitual thought patterns and perceptions. I don't think it is a question of whether this happens, but to what extent and under what set of circumstances.

    I'm inclined to think that intensity and intent are a very important component. At times I would even go so far as to say that if you are not pushing the limits of normalcy then you are simply recreationally passing time. Change occurs in a crisis. I think this was a key element of the mystery school initiations.

    I look forward to reading more articles on your meditation experiences Bergen.

  • Comment Link Bergen Vermette Tuesday, 21 June 2011 04:13 posted by Bergen Vermette

    Hey OV, man I'm so sorry I never replied to this great comment, but seeing your name elsewhere on the site today I remembered that I never got back to you here. Forgive my slip-up :)

    Very cool to hear that you have such a consistent meditation practice. I can't imagine how good it will fell when you crack day 365! I keep track of days and time also, because I find it bugs the heck out of me when I miss a day. It happens though, and usually end-up meditating for only an hour a day about 5 times per week, and 3-4 hours on sundays. Like you, however, I find that the greater the consistency - and duration - the greater the results. Like most things I guess, right. I just completed an all night meditation this past saturday night with about 25 friends and we kept on going through into sunday afternoon. We were joined in spirit by about 20 others from different cities around the world. I needed no rest on Sunday and the day was smooth as silk - I guess all the wrinkles of the psyche got ironed out!

    I appreciated your comment that in centring prayer you don't have insights or observations. This reveals an oversight of mine in my last comment when I said I was interested in the insights illuminated by meditation. I overlooked the fact that there are different types of practices that might lead to the same goal - Union - but travel a different path. Thanks for the reminder.

    As per rewiring the brain, I've been thinking about that over the past little bit, and if we're specific in what we're meaning, I think you may also be on to something. In my experience it's true that certain patterns of thought occur repeatedly. As do emotional experiences. Especially with the emotions (as in PTSD) the body reacts to them almost like a drug hit. Whatever it is that's secreted by the brain, the body seems to get used to it after awhile - like caffeine of something - and the mind enjoys taking you through the same emotional loops to get that chemical hit. I was reading something the other day (can't remember what) and it was saying something of a similar effect to what you're saying - that once a patter is laid down, it can take a long time to break free of it. In this sense, I think meditation could rewire the brain. Because mediation - at least the kind I practice - breaks the pattern, thereby making the brain send out less chemical hits over time. Meditation breaks the pattern by having no relationship to the thoughts arising in awareness. It stops you from chasing thought and reacting to thought. If practiced correctly, this would break the cycle of emotional loops and chemical hits. In a sense your brain would be rewired. Does that make sense?

    And I completely agree with you about intensity and intent. In my experience they make all the difference. On this note, I recently heard Andrew Cohen say that thousand of people, each year, practice the same mediation technique that the Buddha did. But they're not enlightened. The difference? Intention. When Gautama sat under that tree he declared that he would not get up until he was enlightened. How's that for intention.

    Thanks again for the great comment, OV.

  • Comment Link OV Thursday, 23 June 2011 04:50 posted by OV

    Thanks for the reply Bergen. I just got back from a couple of days of silent retreat out on Bowen Island. Nothing formal, just went into the woods, actually a little grassy clearing surrounded by trees, did my usual meditation practice but was finding that laying in the sun working on the tan was having a very similar quieting of the mind as meditation does. Did some journaling work, and the journal I ran out of the house with turned out to have some very relevant information from a self empowerment type course that I had taken five years ago. It wasn't an intense ordeal these last few days, I took food and water, and a sleeping bag, and I slept both nights, so in many ways it was like camping without the tent and fire.

    There are different types of meditations. Some Sunday mornings, in addition to the centering prayer, I connect with others that are doing a heal the earth sending love type thing and those usually result in big smile and lots of tears, really emotional. It's different then the centering prayer because I intentionally hamster wheel thoughts (these are positive rather than negative however). I think I should start doing these more regular and perhaps even try to get a group setting together. Jean Hudon has been promoting these for a long time now and sends out a theme and a few stories just to get everybody on the same page. Thanks for telling me about your own group meditation, it encourages me to take more of a commitment with this one. The link to the current session up to end of July is below.


    As for the brain wiring, have you ever done any work with neural net computer programming. I looked at it a bit back when I was taking computer science and it is based on how some people think the brain works, basically well worn paths become more well worn and those that aren't get used less all the time, the determining criteria being if the path takes you to another useful node rather than having to backtrack by popping off the stack. I think that's the theory, it's been awhile, and most of the material I looked at had less to do with theory and mostly on how to setup your graph and define the nodes, etc and it becomes just another programming language. In the brain it isn't code, but rather inhibition or sensitizing at the synapses through dopamine, serotonin and other chemicals, which aren't random events but depend on your thoughts and experiences so there is this connection between physical brain and conceptual mind. Fascinating stuff and I wish I knew enough to talk about it.

    Guatama had intention for sure. Even at the best of times the ego is a tough nut to crack.

  • Comment Link Corissa Monday, 03 October 2011 19:29 posted by Corissa

    Great article. I've been wanting to try a session after hearing so much about sensory deprivation! For those that live in Vancouver can you mention where your friend is located, or a site/email that they can be reached at?

  • Comment Link Bergen Vermette Monday, 03 October 2011 22:15 posted by Bergen Vermette

    Thanks Corissa. I didn't realize that link for the Float Tank had gone dead. I contacted my friend and he said that he's closed down for the moment but hopes to open again soon at a larger facility in Vancouver. Apparently there's quite a bit of interest in it and he hopes to open a sort of yoga-slash-float-studio. Which would be kinda cool I think! I'll up-date the comments here when I hear about anything more. Thanks for stopping by and glad you enjoyed the article.

  • Comment Link Denis Wednesday, 15 August 2012 06:40 posted by Denis

    Hello Bergen, thank you for the article. I tried contacting but their email is no longer in service. Would you happen to know how I can connect with them?

    Thank you.

  • Comment Link Amber Skye Saturday, 01 September 2012 22:35 posted by Amber Skye

    Is closed? I emailed them and it bounced back.

    I know they are friends of yours, so I'd love to know. :)

  • Comment Link iryna Monday, 29 October 2012 17:38 posted by iryna

    how can i contact this place every time i email them it bounce back . please let me know thank you

  • Comment Link Michael Zaremba Wednesday, 31 October 2012 06:16 posted by Michael Zaremba

    Hello Good People,

    Float Vancouver has been closed for a while.
    BUT, they are re-opening with a ROAR! We will be opening a 5-tank float center in downtown Vancouver in the New Year!

    However, Float Vancouver is no more, we would like to introduce you to Float House, Vancouver's only center for REST, Restricted Environmental Stimulus Technique/Therapy, aka Floatation Therapy, or simply Floating.

    We'll have our FB up soon where you can follow our entire process and progress!

    Tanks for reading!!

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