Right now you are reading this magazine. Chances are, out of the corner of your eye you can see other people, buildings, furniture, trees, the seat in front of you on the plane, or maybe a relaxing view of the ocean. And you can hear music, people talking, the wind, the waves, engines, phones ringing, a distant burglar alarm, dogs barking or perhaps even zebras snorting. You can smell the perfume of the person next to you, coffee brewing, the smoke of someone’s cigarette wafting on the breeze, wet dog, rain on dry earth, baby powder, or your neighbours braaiing. You feel the smoothness of the paper in your hand, the edge of the seat on the back of your thighs, the sun or the wind on your face, and the pressure of your shoes on your toes.

Bet you hadn’t even thought of any of those things. You’ve learned to cut them out because you have to. You’d go crazy if you didn’t. But what does it cost you to keep those sensory barriers up? What are the mechanisms we use to block off more than half of what’s happening outside? Well, no one can really answer that question, but there has been research into the benefits of shutting off that sensory overload.

The first recorded research into sensory deprivation (which sounds quite nasty but isn’t) was by US neuroscientist John Lilly. In the 1950s he built a pretty scary sensory deprivation tank in which student guinea pigs (and Lilly himself) floated on warm salt water, in the hope of finding out whether the human brain could function without any external input. It was a bit of an odd experiment, but then Lilly also experimented with hallucinogenic drugs, claimed to be able to communicate with dolphins, and participated in the search for extraterrestrial intelligence, so “odd” is relative.

It could have ended there, but Lilly found that not only could the brain function without external stimulus, it functioned superbly. Time spent in the isolation tank resulted in increased creativity, greater concentration, less stress and generally improved well-being. So, over the next couple of decades, a number of people worked on improving his original design. It was a long process, but the result is that the flotation tanks in use today are aesthetically, ergonomically and technically vastly superior to Lilly’s rather crude prototype.

Also known as restricted environmental stimulation technique (REST), floating is increasingly entering the mainstream as its therapeutic benefits become better known. The main advantage of floating is that, by cutting out all external stimuli, it achieves in an hour what it takes Eastern yogis a decade or two to master – a quiet mind. A quiet mind is something we almost never experience in our busy lives, so most of us don’t really know the benefits.

There’s a whole lot of jargon we could go into, like theta waves, alpha waves, etc., but whatever Greek alphabet soup we throw at it, the basic principle is shutting out the constant chatter. Instead of buzzing about nothing or about everything, our minds are calm, turned in towards ourselves and, some say, effectively accessing our unconscious. This is where healing takes place – emotional and psychological healing certainly. But evidence is increasingly showing that by regularly entering a state of quiet mindfulness we can heal chronic pain, bring down blood pressure and cholesterol, and generally improve our physical well-being. OK, it’s not been properly researched with double-blind clinical tests and things, but the anecdotal evidence is strong, so it seemed like a good idea to give it a try.

A flotation tank is, basically, a giant bathtub with a lightproof roof. It’s ventilated so it’s not stuffy and, of course, it’s filled with a warm, viscous liquid that, as far as we can imagine (because most of us can’t remember), accurately mimics the sense of pre-birth immersion in amniotic fluid. It’s really just water with a lot of Epsom salts dissolved in it to increase the density.

The process is simple. You arrive, shower, pop in some single-use ear plugs, and then climb into the tank. It takes a while to adjust, but soon you find you can’t quite feel where your body ends and the liquid, or even the air, begins. There is no pressure on you anywhere, no sound and no light. As you relax, it feels like you’re sinking deeper and deeper, but you’re not going anywhere. It’s just that, in the normal course of your day, there’s no moment when some part of your body isn’t supporting your weight – even when you’re asleep, your back or side and legs and arms are supporting your body and there’s pressure from the mattress. And when you lean your head into the pillow, the pillow leans back into you.

But in the float tank, you are free – free from gravity, free from the need to hold yourself together. As you sink deeper and deeper into relaxation, your blood pressure drops, your breathing slows down, and the tension in your shoulders and back is eased. It’s almost like your body takes the opportunity to literally straighten out the kinks. It sounds weird and it takes a while to get used to, but once you learn to trust the process, it’s a powerful healing modality.

And, yes, your mind quietens. Some people enter a space that’s almost trance-like, others just relax totally. And a surprising number find that, during or just after a float, the solution to an apparently insurmountable problem, or the perfect phrase to end that presentation, simply pops into their minds. It’s not just the body that sorts out the kinks – it’s the mind, too.

This is the question most often asked. All guests shower, wash their hair and rinse carefully before entering the tank. The tank is sterilised with ozone at regular intervals and also between clients.

The Epsom salts is actually quite soothing, but can be irritating to the delicate skin in the ears, so ear plugs serve two purposes – to help cut out sound and to protect your ears from the salts. If you have insect bites or small wounds, these might sting. As for your eyes, you float so high that they are nowhere near the water. There may be some mild itching at the beginning, but it will go away as you settle. After the float, you will have a quick shower to rinse off the salts.

It’s a good idea to have a small meal a few hours before floating so that your blood sugar is stable. Don’t shave or wax prior to floating, as then the salt may sting

You’re likely to be feeling very mellow, and you should make a point of drinking plain water or herbal tea to prevent mild dehydration.

A very few people find it difficult to relax, and can’t seem to settle down. If this happens to you, it’s not a big deal. It’s not like you’re locked in there – you have control over the door, the lights, everything. This is not Fear Factor, so you can leave whenever you want to. But it’s worth persevering.