A few weeks ago, at a semi-detached house in Devon, a group of friends gathered to witness the birth of a baby. To an outsider the gathering had the atmosphere of a religious ceremony. The tiny sitting-room was decorated with house plants and carnations, while four women sang ethnic songs and chanted. Two NHS midwives were also on hand and a photographer stood ready.

In the middle of the room stood a large water birth tub, where Carmella B'Hahn laboured in womb-temperature water. Beside her in the water Abel, her husband, soothed and comforted her. The women's singing built to a climax with each painful contraction.

After a nine-hour labour, Kitte Norgaard, one of the midwives, knelt by the side of the tub to help with delivery. The baby gave a short squeal and took his first gasp of air as she lifted him dripping on to his mother. It was a boy, just like Carmella and Abel's first child.

Baby Asher's arrival completed a seven-year chain of events that has catapulted his parents between the extremes of joy and despair. Their first child, Benjaya, was born amid the flash of cameras in Britain's first widely publicised water birth. In early 1992, aged five, he drowned in the river Avon near his home in South Brent, Devon. Despite the drowning, Carmella decided to have another water birth.

The B'Hahns' story begins in 1986. They were living with Carmella's parents in Clent, near Birmingham. Both were members of the New Age movement, and helped to run a centre for holistic education. Carmella was expecting Abel's child.

At that time only a small number of British women had tried water birth. Carmella was half-way through her pregnancy when Abel suggested it.

'At first I said no,' recalls Carmella, now 35. 'I thought it would be a complication, especially as I planned to give birth at home. The thought of introducing water as well, of which the medical profession had so little knowledge, seemed too much to think about. But Abel gave me a book to read and an uncanny thing happened. As I was reading the chapters on water birth I felt a lot of stirring inside my womb. A few days later I picked up the book, and off it went again, this movement inside. It really felt to me as though there was some connection.

'I thought, how am I going to find out if this is my imagination, coincidence, or what? So I sat on the bed. I thought, OK baby, if you can hear me, I would like you to give me one large kick if you want me to have a water birth. Then, pow] One large kick. I could actually see the skin move.'

After this vote in favour from the unborn baby, the next stage was: how? They didn't have much money and there were few purpose-built tubs then. Abel found the answer: a plastic fish pond, 16in deep, bought from a garden centre and supported with a home-made wooden frame.

Then, as now, Carmella invited a 'support team' to be in on the birth. Among the dozen people present were her parents, her sister, her sister's boyfriend and even the lodger.

She admits that birth shouldn't be thought of as a spectator event. 'On the whole it's probably not a good idea to have a lot of people present, unless those people can act as a team and be of one mind, there to serve the woman completely. This group of people were.

'I had no intention originally to call them in, but just before the second stage of labour I knew I had to have them in the room. I sent for them. They all came in and sat perfectly still, just giving out. They were all there because they loved me. I felt as if I was giving birth into a supportive cocoon of love energy.'

The birth made headlines: 'Little Ben swims into the world', 'The baby born in a fish pond'. An exquisite photograph taken moments after the birth found its way into newspapers and magazines worldwide.

Six months later, Abel and Carmella married in a self-styled ceremony. They even designed their own marriage certificate. Money from the sale of their story and photograph went into their research into water births. They moved to Devon and developed a business called Birthworks, manufacturing and supplying birthing tubs.

Meanwhile, Benjaya set about quashing any idea that water babies would be calm and passive. Abel, 36, says: 'He was bloody hard work. He got colic and slept badly for the first 18 months and was very hard. But at the same time he was very charming.'

Carmella recalls his growth into boyhood: 'He was a ball of fire. He was strikingly handsome, with enormous brown eyes. He tested us to our limits. But he was also extremely sensitive.'

On 28 February 1992, Carmella left for a childbirth conference in Sussex. Later that day, Benjaya played with two friends by the river behind Abel's workshop. He tried to climb down a steep slope to a small pebble beach, but slipped and fell into the water. He was swept away. His body was later found 300 yards downstream.

The couple were devastated. And because of the way Benjaya died, they were again the focus of publicity. Newspapers treated the drowning as a tragic coincidence. But Carmella has always disagreed. 'I don't believe in coincidences,' she says. 'I feel that the way he died was an absolute blessing. It makes it so much easier for me that he was taken by nature, by the element of water with which we work.

'His finale was just so perfect, as if he'd played out this drama, beginning by him coming into this pool of water, to the end being found in a blaze of publicity in a pool of water. Obviously we wouldn't choose the death of our son. But it's hard to get that across to other people, for whom it is an absolute tragedy.

'I was on the train to London to do a conference the day Benj died. I spoke to Abel on the phone. He said to me: 'Benj has had an accident - he's fallen into the water.'

'And when I heard the word water, from that second onwards it was 'Oh - it's water'. So it kind of fits somehow. As if there was some kind of divine chess player moving things in exactly the right places.'

The death also had a profound effect on Abel. Carmella says: 'His relationship to children since Benj's death has radically changed. Kids run across the street now to throw themselves into his arms. It wasn't like that before.'

Abel says: 'I wasn't particularly interested in children before. I didn't really know how to relate to them. I was very much involved in myself, in a way. At the time I didn't recognise that children are a wellspring of love - they don't withhold it, temper it and do things with it the way we do.'

Carmella was five weeks' pregnant when Benj died. At three-and-a-half months she lost the baby. A few months later she was pregnant again, but lost that one, too.

The miscarriages hit them both very hard. 'Being pregnant had provided me with a continuity of life which I'm very grateful for, because it was as if motherhood hadn't ended. Obviously, it did end when we lost the baby.'

Last autumn, while Carmella was expecting Asher, controversy broke over whether water births were safe. But the scare and Benjaya's drowning did nothing to put Carmella off water birth.

Today, as she cuddles baby Asher (his name means The Laughing One), she says: 'The more time I spend with him, the more I come to realise he's startlingly like Benj. He's not quite a carbon copy, but almost.

'I know they're different people, different characters, and we'll never have back the little boy we have lost. But there's something about them looking so much alike. It is almost as if he's here again.'

(Photographs omitted)