With its lush tropical surroundings, year-round comfortable water temperatures, ample proportions and kidney-shaped curves, this pool is for me one of the big attractions of living on Phuket. Every day I swim in its translucent blueness. I swim with my arms cutting great arcs through the blue water and, as I turn my head above the surface to breathe, I glimpse for a split second a line of coconut palms. At dusk or dawn, the swaying heads of these elegant palms are silhouetted against a low sun or crimson sky.

Sometimes I swim as if in slow motion, holding my head down for two or three breaststrokes while expelling the air slowly through my nose. Bringing my head up, I take a big gulp of air through my mouth and then breathe slowly out again through the nose with head under water for a few more strokes. Some years ago I read in an old yoga book from India, now long out of print, about this form of yogic swimming.

After a little practice you establish a rhythm. Don't ask how or why it works, but the excercise seems to wash away stress and anxiety, creating a heightened feeling of well-being. Don't we usually feel better after a swim? The book also claims that yogic swimming helps those who are on the large side to reduce weight, while adding pounds to the underweight. Though I have yet to verify this claim, I guess the theory is that these simple breathing exercises balance the metabolism in some way.

Just as a hydroelectric dam can convert water into electricity, so the power of water can be harnessed for the benefit of our health. At the Evason Spa and Resort in Rawai, on the southern end of the island, a Swedish yoga teacher practises a form of water therapy. Immersed up to her shoulders in one of the resort's pools, she demonstrates tai-chi movements while extolling her students to feel the texture and mass of the water and even to dance with it. Part of the routine is to be supported on the surface of the water by a partner with his or her arms under your head and hips while the water takes most of your weight. It’s is a remarkably relaxing sensation.

A similar type of water therapy was developed less than a decade ago at a hot-spring resort in northern California, where it evolved into a semi-structured body of practice known as Watsu, an abbreviation of “Water Shiatsu”. According to the promotional literature, Watsu’s “gentle rocking movements, stretches, and nurturing support in the arms of the practitioner convey receivers to the peace and simplicity of their earliest childhood and womb states, allowing physical and emotional blockages to be gently released. Above all, Watsu is deeply relaxing, guided by a philosophy of gentleness, complete acceptance, and unconditional love.”

Though all this might sound too much like New Age hype to some people, Watsu is apparently widely practised by therapists in clinics, hospitals and spas in the US, Canada, Japan, Australia, Europe and now – in a modified form – on Phuket. If you have access to a pool or when the sea is calm in the dry season, Phuket is the perfect place to practise this form of gentle therapy because the water temperature at most times of day and at most times of the year is comfortable, neither reducing nor increasing the body temperature.

Water therapy of one sort or another has been around since antiquity. For the Romans, thermae, precursors of today's spas, were centres of hygiene and sociability in every town where people relaxed and de-stressed in the soothing embrace of hot vapours. In ancient Greece the health benefits of swimming were widely appreciated.

In the 16th century an English doctor, Timothy Bright, travelled to Europe and discovered the therapeutic benefits of drinking mineral water, at the same time coining the word "spa" after a town in Belgium. Europeans travelled far and wide to “take the waters”. Places such as Baden-Baden in Germany and Bath in England, with their mineral springs, became popular resorts for those seeking relief from their aches and pains, skin problems, asthmatic conditions, TB and many other complaints. Not long afterwards, Brighton, England (where I come from) became a fashionable resort when a certain Doctor Russell proclaimed the health benefits of bathing in - and drinking - cold seawater. The rich and elderly and young and languishing all trundled down from London to Brighton in their horse-drawn cabs to immerse themselves in the chilly brine from bathing machines (bathing huts on wheels used to protect the users' modesty).

In her satirical novel Sanditon, Jane Austin caught the mood of the day: "No persons could be really well or in a state of secure and permanent health without spending at least six weeks by the sea every year. The sea air and sea bathing together were nearly infallible, one or other of them being a match for every disorder of the stomach, the lungs or the blood. They were anti-spasmodic, anti-pulmonary, anti-septic, anti-bilious and anti-rheumatic. Nobody could catch cold by the sea; nobody wanted appetite by the sea; nobody wanted spirits; nobody wanted strength."

The health benefits of hot springs, as opposed to cold seawater, are acknowledged in many countries. The Japanese are probably the world’s leading practitioners of hot-spring bathing. The mountainous, volcanic landscape is riddled with natural springs of various temperatures and chemical ingredients that are said to alleviate a range of ailments. Japanese people flock to hot-spring resorts, some of them very luxurious and expensive, for both health and leisure. Thailand also has a small share of hot-spring resorts. Some establishments around Ranong, on the northern Andaman coast, attract local and foreign residents while the new and well-appointed Dusit Hot Spring Beach Resort and Spa just north of Phuket in Phang Nga Province is becoming popular with lovers of this form of healthy leisure activity.

The resort has the use of the only privately-owned hot spring in all of Thailand and is surely unique to the Kingdom in terms of its facilities. The constant supply of hot mineral water, at a temperature of over 40 degrees Centigrade, bubbles up within attractive, circular tiled pools. When you’ve had enough heat - and it's not recommended that you stay more than 15 minutes in the hot mineral water at any one time – you step into an elegant freeform pool of ambient temperature to bring down your body heat. Here you can lounge in the water and massage yourself on powerful hydrotherapy jets just under the surface.

Dusit Hot Spring Beach Resort and Spa – no relation to the Dusit group of hotels – also boasts skilled massage therapists, trained by a former manager of the Banyan Tree Spa, as well as nicely designed massage salas, 24 private guestrooms and an excellent restaurant. All in all, this fine resort and spa by the sea makes a very good place to give a tired body a truly relaxing mini-break.

Much research has gone into the study of the health benefits of bathing in hot mineral springs. In general, it seems to be agreed that natural hot springs cleanse and beautify the skin, sooth muscles and joints and ease tension. Some of the chemicals in the water, such as calcium, are thought to aid the function of muscle tissues, while iron helps the formation of red blood cells. Furthermore, a recent study published in the New England Journal of Medicine shows that regular hot spring bathing reduces blood sugar levels by about 13 percent in those suffering from Type 2 diabetes millitus.

As well as enjoying hot springs, Thais love to visit waterfalls. Sitting in the cool air in the shade of tall trees within range of the sight and sound of tumbling cascades can be a refreshing, mind-calming, even healing experience. Some waterfalls are believed sacred, and some are thought to be inhabited by spirits. As an indication of their significance, throughout history members of the Royal Family have made special efforts to visit them. In the south of the country, for example, at Than Sadet Falls on northeastern Koh Phang Ngan, nearby boulders are carved with the royal insignia to mark the visits of Kings Rama V, Rama VII and Rama IX. Water considered sacred from some falls and pools are used for ceremonial purposes such as coronations.

Water also plays a symbolic part in the Songkran Festival, which takes place in April in towns and villages throughout Thailand. Described as the world’s greatest waterfight, the festival has become an opportunity for people to fire water guns or throw buckets of water at complete strangers. If you're on any street in Thailand at this time of year – especially in Chiang Mai, where the festival is celebrated with special enthusiasm – be careful how you go; you could get your camera doused and seriously damaged.

Though much of the original meaning of Songkran has been lost over time, part of its excitement is the expectation that the slow and tedious days of the hot season will soon be forgotten with the coming of life-giving rains and the annual rice planting. With a sense of fertility in the air, it is said that girls are encouraged to become rather bolder than traditional girls normally are, and, unsurprisingly, many romances are sparked at this time. Songkran is also a time where young people pay respect to their parents, elders and teachers, and forgiveness is asked for wrong-doings committed over the previous year. Blessings are made with drops of sacred water.

Blessings of sacred water are a standard part of temple rites and ceremonies. When someone is thought to be possessed by some sort of evil spirit, monks splash water over the person’s head as part of an exorcism – another example of water’s healing power. Sacred water is also used when a man's head is shaved during his initiation ceremony to become a monk.

The feel of water in a parched throat or on dry lips; the sight of a still lake or the sea at sunset; the sound of a waterfall, the rhythmic beat of waves or the patter of gentle rain - all the senses of water can be soothing and healing. But for me, the most calming water-related sensation of all is floating on my back at night in the sea off one of Phuket's beaches. Stretched out on a bed of black liquid I feel as I'm gently held in the earth's palm. Above, the darkness is pierced by a handful of diamond-sharp stars, light-years away, reminding me of my own inconsequence. But the sound of my breathing reassures me that it's good to be alive.

Tension and stress seem to seep out through the pores of my skin and dissolve into the ocean. The longer I float and breathe, the more stars perforate the canopy of the thickening night, and the more I appreciate the healing powers of the sea.