h A sensory deprivation flotation tank almost drowned me / saffron huang / blog

A sensory deprivation flotation tank almost drowned me

September 14, 2020

Yesterday, I almost drowned in a sensory deprivation flotation tank when my hair was sucked into the filtration system. I was not told about much of the actual float procedure nor the existence of an emergency button, which I couldn’t reach anyway. No one was meant to check in on me. This is a horror story about losing agency to an automated system featuring, as I discovered, no real contingency plans.

I turned 23 recently. For my birthday, a few of my friends gave me a float voucher as I’d mentioned an interest in trying it. It’s the kind of unusual sensory experience that piques my curiosity. But at $100 NZD for an hour-long session, it’s also a potential source of buyer’s remorse that I’d prefer someone else pay for. A birthday, I figure, is an excuse for frivolity.

As the only employee on duty, let’s call her Anna, was stepping me through the procedure, I asked her, “Should I tie my hair up?”

“No, don’t worry about it,” she responded. She told me about the extreme salinity of the water, and that there was a blue button in the tank to turn the lights on inside—but that in the interests of full relief and relaxation, it was best to lay in complete darkness. I was instructed to shower before getting in the tank, and as I was doing so I once more casually thought about tying my hair up. I decided against it, since I was told to shower again afterwards and it would be a hassle to untie wet hair. Anyway, there seemed to be no benefit to it, as espoused by Anna’s response.

I got out of the shower and put the earplugs in, as she’d advised, to keep the water out of my ears. I dipped a foot into the tank, testing the warmth of the water. I could almost taste traces of salt in the air—apparently, there were 5kgs of epsom salt dissolved in this small pod. This would be more than enough to keep me afloat. Anna had told me not to touch my face, and particularly not my eyes; the heavy sting of the salt would quickly spoil any attempt at tranquility.

Music would play for the first ten minutes and the last five minutes of the hour-long float. The initial music was intended to relax me; the music at the end would serve as the signal that my time was up. As I laid down in the water, I pulled the lid of the tank down. The lights both inside and outside the tank slowly blinked off.

Feeling both curious and skeptical, I made mental note of what I was experiencing and how I was feeling. I could move my limbs around entirely frictionlessly and weightlessly, so I did that. I tried pushing my arms down and felt the resistance of the water’s salinity. I lightly paddled my hands and felt waves of water sweep up my body, brushing my face. I couldn’t yet tell if the muscles in my neck or shoulders were any looser. I tried to meditate on my breath. As my eyes adjusted to the dark, sparks danced across my vision, and faded. (Unfortunately, I can’t report actual hallucinations, which some people experience.)

I could barely hear the music through both the earplugs and the water it kept out. I planned to text my friends afterwards with jokes about returning to the womb, slipping around a watery cocoon in absolute darkness and, once the ten minutes of music ended, absolute silence.

It’s common to fall asleep during a float. I read the business’s online FAQ, where they reassure floaters-to-be that they wouldn’t drown if they fell asleep. The salts would keep them afloat, and if they were to turn over the water would immediately wake them. I really lost my sense of time in there, but I think I became sleepy and hypnagogic perhaps 30 minutes in, and—although I made some attempt at staying alert—I started drifting in and out of wakefulness.

At some point I felt a mild tugging sensation on my scalp. Hmm, weird. I thought it was just my head bumping against the side of the tank, but I felt around with my hand and found that a good chunk of my hair had become pulled into a head-height vent at the top of the tank. This was not a few strands; it was, if compressed, a coin-sized diameter of hair being pulled, leaving increasingly little length from the skin of my scalp, and increasingly little freedom of movement.

Fuck. I had to get loose. My face was only an inch above water. Maybe if I pulled with all my body’s might, I could free myself. Adrenaline surged; I tugged as hard as I could, and in the process I flipped over and swallowed a mouthful of disgustingly salty water. My eyes stung, hard. When I eventually was able to come up for air and still myself, I spluttered and spat out water, and told myself that my first priority was to keep my face up, and stay calm. Drowning in a flotation tank was not going to be the way I died.

My hair was so solidly ensnared in the vent that there was no way I could pull the strands loose, or break them off. A mere bundle of keratin is unreasonably strong. I tried to tie the rest of my hair up with the hairband on my wrist, bunching it in an attempt to prevent more from being sucked up.

I’d seen a red button near the opening of the tank. No one had told me what it was, but I figured that was the emergency button. (Later, Anna told me that it doesn’t work, anyway. Even later, her manager disputed that claim, saying that the emergency button does work. As you can see, things are maximally confusing.) However, as I was glued to the other end of the tank, I couldn’t reach it.

I yelled into pitch black.

HELP!!!

I wrenched away the earplugs, trying to hear anything. No response.

I kicked, and managed to get the lid of the tank up a little bit. I told myself I just needed to hold on until she came to check on me, but I had no idea how long that might be. I couldn’t see, I couldn’t hear, I was floating in water and unable to free myself. I have something of a phobia of drowning; every time I’ve had to swim in deep bodies of water (e.g. for “fun” school activities), I’ve been unduly anxious. I was very aware of the perimeter of water partially submerging my face, ebbing up and down. I tried not to hyperventilate—not endangering my breath was very important. I felt entirely vulnerable, and entirely terrified.

I yelled a few more times, and finally I heard her anxious voice at the door. “Are you alright?” “NO?!?! I’m trapped!” Eventually, “Can I come in?” What the fuck, please come in!

She was on the phone with her manager as she tried to figure out what to do. I told her to get scissors.

“I’m shaking,” she said as she worked on cutting through my hair.

I sat up and coughed heavily, trying to expel the water from my system. When I looked in the mirror, my hair looked like it was done in a giant messy bun at the crown. And that was the part that wasn’t tied up (in fact, I’d only managed to tie a small amount with the hairband). It was that tangled. My eyes were salt-swollen and red, and the drying crystals had started to cake my face. I felt so sad, and so relieved.

“You told me not to tie my hair up!” was the first thing I blurted when I eventually came out to the front desk.

“Well yeah, you didn’t have to!”

I was stunned. “What?”

“Didn’t you hear the music?” Anna asked me as a response.

Apparently, the five minutes of music at the end and a voice instructing me to leave the tank should have been my cue to get out. I also learned that a filtration system automatically starts to pump after the music ends. But with the earplugs in as instructed, and having either fallen asleep or been in a state of hypnagogia, I couldn’t tell her whether the music had actually played or not. Even if it had played, the initial music had been so faint, I doubted its ability to wake anyone. Again, it’s common to fall asleep in a float tank, as it is deliberately relaxing. In fact, some people intentionally sleep in one at night. I’m not a heavy sleeper, either; I never miss a morning alarm.

They programmed the tank to start the filtration immediately, without effective alarms, or checking that I’d actually gotten out. There exist flotation tanks with sensors, which could have automatically delayed the filtration process until no movement is detected; at the very least, a gentle knock on the door informing me that my time was up doesn’t seem much to ask. Anna said that she’d noticed I wasn’t out after my session and hadn’t turned the shower on yet, but thought nothing of checking on me to see if things were going okay.

The manager called me tonight, which was illuminating. I found out that:

  1. I had not been told that there was a correct orientation to lie down in. My head should have been near the opening of the tank, but it was towards the end with the vent. (Although it seems from Google Images that people have laid in it both ways.)
  2. I should have been told that the emergency button existed and how to use it. I’d only inferred it from seeing the red button.
  3. I should have been walked through the entire flotation system, and been informed that the filtration pipes would start after my session ended; I was not.
  4. The music at the end is supposed to be a soft, gentle awakening, not a loud alarm, which confirmed my suspicions. Especially if they also advise putting in earplugs, I think they should have mentioned that it might be hard to hear.
  5. In her experience, 1 of 50 people sleep through the music and have stayed in there once the filtration starts. I assume that none of them have gone in the wrong way or had long hair. If they knew that people do sleep through the music, I wonder why it was not procedural to check on me. I had to yell multiple times to get any attention.

She told me that she would run tests on whether the music had been loud enough in my specific tank, and placed a lot of blame on Anna, the only employee present, who had worked there for only two months. She was clearly very concerned about her business; as a result, it’s hard to know whether the procedures that she claimed are normally followed are actually in practice.

It seems like multiple parts of the system were ill-considered, or simply collapsed. I was incredulous. I’m the type of exacting user who carefully remembers and follows instructions, I was entirely sober, and I have no health issues unlike many of their other customers. According to the manager, people with PTSD, anxiety, claustrophobic tendencies, and so on come in to float, often looking to heal. If something like this had happened to one of them, they’d probably be much more traumatised, or worse, dead. There are plenty more creative ways that this could have gone wrong. My own “missteps" were not particularly crazy: I wasn’t informed that there was a “correct” way to get in the tank, and I wasn’t woken up by the music. Two laughably mundane mishaps were enough to create a potentially life-threatening situation.

The most important thing at the moment is processing my emotions, but I can’t help but point out the more general relevance of this experience, which is also a very personal issue for me. Implicitly and explicitly, I was asked to trust—and did trust—the interlocking system of technology and humans that constituted this sensory deprivation tank experience. It is intended for my benefit, and I’m advised to surrender and relax inside it. Many more vulnerable people look to this to try to heal from physical or mental distress, trusting themselves to the process. This is a particularly poignant example of how everyday, as we interact with the designs and impressive feats of engineering that constitute our world, our trust is asked for and necessarily given. As users meandering through, we can’t know it all.

But the products of human agency tend to evade human control. This was clearly not an intended outcome, but it was certainly a foreseeable one. What is more egregious is that there weren’t multiple, layered contingency plans for failure modes, foreseeable or not. Okay, I wasn’t told about the emergency button, and I wasn’t able to hit it. Even if I don’t call for help myself, there should be someone checking in. It’s an hour-long float in water in an utterly isolated, enclosed space, an experience new to many—if someone had an anxiety attack and couldn’t find the button in the dark, there were no safety systems to catch them. Important side note: Both anxiety and ketamine cause dissociation, and ketamine use is known to kill people in sensory deprivation tanks. Please be very careful about floating if you’re prone to dissociation, and definitely don’t take ketamine and try this.

I had consented to be stripped of my senses inside an unfamiliar apparatus, but that was consent based on the assurance that they knew what they were doing. That degree of trust, the belief that it was a controlled relinquishment of autonomy, made the fall all the worse. I had no idea that the preprogrammed agency of the flotation tank would take all of my own agency away from me. After I got out, I cried and held Anna’s hand, telling her how scared I was of the possibility that she wouldn’t come.

I’m still a little in shock. The lingering burn of the salt water is still in my throat, the top of my head is tender, and my neck hurts in new and strange ways. My hair looks surprisingly normal, but I’ll get a haircut tomorrow.

I’ve been tenderly prodding my recollection of that visceral feeling of helplessness, of knowing there was nothing I could do to free myself from this machine. I can’t really help it—it’s a sore, new wound that I can’t leave alone, located somewhere unknown inside my body. It is a painful warning of how we unavoidably trust systems, and how we must design them accordingly. As things become more automated and more artificially intelligent, this is an intimate reminder of why I care about building safe AI.

When I touch this emotional memory, I’m also touching a profound sense of my own fragility. Sometimes, there’s literally nothing you can do but try to breathe and stay afloat. I can’t be sure how close I was to dying, but what matters, and lingers, is the emotional experience of thinking that it is a very near possibility.

Bodily danger feels very different to purely psychological danger. I’m lucky that I don’t feel so breakable on a daily basis; most of us don’t normally shoulder an awareness of being physically, mortally threatened. But at some level, I have to feel grateful to be confronted with an emotional taste of the knowledge that I am—life is—that frail. There are things that, as flesh and bone, I just so obviously cannot conquer, even as I go through life believing in my agency. Losing agency is, perhaps, one way to understand what having agency means.

(Written on Sep 13)

Note on Sep 14: If I’ve talked to you about this in the last few days, thank you so much for helping me process it. You are wonderful. Also thanks to Nick Cammarata for suggesting the point about anxiety, ketamine and dissociation.

I’m not sure about legal action. What I would really like to do is help prevent this experience from happening to anyone again, specifically within a flotation tank but also more broadly, in interactions with any technology. I’ll figure out whether pressing charges gets me there, or if something else does.

Another bit probably worth mentioning: New Zealand has almost no new cases of COVID-19 at the moment, and we are not under lockdown, so you needn’t be worried about my virus exposure.


thoughts welcome here