I have been intrigued by the idea of experiencing sensory deprivation - no, not a Guantanamo Bay interrogation technique, but something more salubrious and enjoyable - ever since I read Nobel Prize-winning physicist Richard Feynman's fascinating descriptions of hallucinations he self-induced when floating in an isolation tank in nirvana-seeking California in the 1960s. His reports of a sensation of the ego leaving the body, accompanied by an other-worldly inner serenity, are reminiscent of a major thread that runs through nearly all Eastern and New Age mysticism - the quest to cancel the constant stimulation of mind and ego in daily life. The isolation tank (also known as a flotation tank) offers the tantalizing potential of attaining "instant karma" and a different state of consciousness - without spending years practicing meditation or yoga in a mountain-top monastery, or experimenting with dangerous drugs. Just add water and go with the flow. Given the seemingly inexhaustible interest Israelis exhibit in holistic therapies and Eastern mysticism, I had a hunch I would be able to find a flotation tank somewhere, and I was right. With one phone call, I was able to book 50 minutes of sensory deprivation (260 shekels - $75 - for a basic session) at the "Private Sea" spa in Tel Aviv, which bills itself as "the first flotation center in Israel." Private Sea is located in a nondescript building above a restaurant in a bland strip mall in the Tel Aviv suburb of Afeka, but from the moment you enter, it makes every effort to make you feel as if you have embarked on a trip to a different destination. The ambiance is suffused with soft light, pastel colors and candles. A large-screen video of kaleidoscope-colored swimming fish runs in a continuous loop in the spa's lobby, while soothing ocean sounds mixed with violin music are discreetly heard in the background. An isolation tank is essentially a large, completely enclosed tank filled with water 25 centimeters (10 inches) deep and 360 kilograms (800 pounds) of Epsom salt. When the entry door to the tank is closed, no light or sounds or smells penetrate inside. The concentration of salt in the water is sufficient to induce floating, as in the Dead Sea, and with the water constantly kept at skin temperature, after a few minutes one begins losing the sensation of the boundary between one's body and the water - hence the experience of sensory deprivation - nothing can be seen, heard or felt, and the salt is odorless. The tanks are equipped internally with easily accessible buttons for opening the door or switching lights and recorded sounds on and off, to enable floaters to control the amount of sensory deprivation they wish to experience. Admittedly, one needn't be hopelessly claustrophobic to balk at first at the idea of climbing into a watery coffin, as some nervous souls describe the tanks. But Private Sea's proprietor, Dany Rudnicki, gives his clients a soothing introductory talk before their first experience to allay any such fears. With "sensory deprivation" having taken on new and sinister connotations, with its association with CIA torture rather than hippy, happy California, that term is out; "restricted environmental stimulation therapy" is in - and the isolation tank is now a "Samadhi tank," Samadhi connoting "concentration of mind as a precursor to enlightenment" in the Buddhist tradition. Rudnicki, who hails from Belgium, opened his center in 2006, several years after undergoing his own first flotation experience abroad. He says his clientÃ¨le include many who are into "holistic" treatments, along with athletes who use the tank when recovering from injuries, and high-powered business executives and diplomats who want to "get away from it all." He ascribes stress reduction and healing to raised levels of endorphins experienced by floaters. In contrast to the coffin imagery, he points out that practitioners of "rebirthing" therapy use the Samadhi tank to recreate the safe and life-affirming experience of being in the womb. After a quick shower and the insertion of wax ear-plugs, to prevent water pouring into the ears, I'm ready to enter the tank. I choose the "total experience" and turn off all light and sound from the first moment. The tank door is shut, and it's just my mind and I cocooned away from the rest of the world. In fact, enveloped in total, silent darkness and with minimal body sensation, it almost feels like I am in a separate, infinite world. And then... Nirvana? Buddha-like enlightenment? Psychedelic visions of dancing pink elephants? Honestly not, but certainly one of the most relaxing experiences I can recall, in both a psychic sense and physically in terms of muscular tension reduction. The sensory deprivation does have a quieting effect on the mind, allowing it to follow paths of its own choosing effortlessly. Time seemed to dilate out far beyond my allotted 50 minutes. I replayed in my mind positive memories and images of people close to my heart. The weightlessness in the buoyancy of the water enabled my spine to stretch to its most natural position. I emerged feeling as tranquil as after a deep massage. Back on the streets of Tel Aviv, the sun was shining brightly. The light filled my eyes, flooding my senses. It felt good. Sadly, in less than the 50 minutes it took to reach a deep state of relaxation, the sensation mostly vanished. Fighting my way home through particularly heavy traffic, I felt tension remounting. By the time I got into bed, a bundle of nerves, the flotation experience was but a sweet dream.