There is a risk of blackout and burst eardrums and the lungs compress to the size of a clenched fist, but deep down at 90 metres – where no other woman swimming with just a monofin for propulsion has gone before – the Red Sea looks golden to Sara Campbell. Britain’s newest world champion is only half-joking when she describes the past fortnight of her life as “breathless”. Freediving is, after all, diving on a single breath without the use of breathing apparatus.

It is, though, Campbell’s three world records – set at the end of last month – followed by a gold medal at the individual World Championships that concluded yesterday in Sharm el-Sheikh, Egypt, that have left the 35-year-old and her rivals so open-mouthed.

The former yoga teacher, who started competitive freediving only nine months ago after selling her London home to move to Egypt, can hold a single breath for almost five minutes. There, Campbell discovered the Blue Hole, the exotic setting for her recent world-record dives of 90 metres in constant weight (swimming down and back up dolphin-style wearing a monofin), 81 metres in free immersion (pulling herself up and down a line using her arms) and 56 metres in the no fins discipline (using breaststroke).

“Amazingly, I didn’t know the Blue Hole existed before I moved to Dahab,” Campbell said. “It’s the big hole through the reef table that makes it special because it has created a huge, vertical tube with protected water. There’s hardly any current and it’s a place of beauty of peace.” Ironically, it was a loss of serenity that propelled Campbell into freediving. “I was in London when the terrorist bombs exploded in 2005,” she said, “and I was also in Sharm and Dahab during those attacks. Some of my friends were caught up in it and I helped set up a support group for the victims. I had some weird emotions and ended up crying at home for three days. I knew I had to do something, so I decided to go diving.”

That meant completing a course run by two of the world’s leading female freedivers – Lotta Ericson and Linda Paganelli. The pupil may have become master even faster, had it not been for a bout of hepatitis A that kept Campbell out of the water for nine months. “That just made me more determined,” she said.

And stubborn resolve made the difference in Sharm el-Sheikh. Freedivers have to declare their intended dive depths the night before competition and Nathalia Molchanova – the Russian who had held all the world records Campbell broke in Dahab – came second in the mind games when she declared 95 metres in the constant weight. It was overambitious, leaving Campbell to complete her declared dive of 88 metres to win the gold medal. “I’m thrilled to be pushing out the boundaries in our young and exciting sport,” Campbell said.

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