Sailing: Pioneer Caffari in her element even when the whole world goes wrong

Somewhere in the Southern Ocean, and Dee Caffari was faced with the inevitable. Nothing for it but to confront her fears and what she describes as a sailor's "worst-case scenario". Climb the mast, over 90 feet of it. "I'm not very good at heights, but we all have to go up the mast at some point to fix something," she says, recalling the moment when she experienced the true loneliness, and terror, of the long-distance sailor during her attempt to become the first woman to sail solo non-stop around the world "the wrong way", against the prevailing winds and currents.

"It's horrendous, you're swinging around and get bruised and battered," Caffari adds. "It feels as though you've done 10 rounds. But you just have to get on and do it. You try and pick good weather. But the boat doesn't always agree with you, and you just have to fix whatever it is, right now."

That is how she found herself in a jam, with an ominous looming presence on the horizon. "I couldn't go up or down. I just looked up and remember seeing this line of cloud, and thought, 'My god, that's the next front'." Inevitably accompanied by pitiless winds and all-consuming seas? She nods. "Then you look down, and there's the boat below, with nobody on it to help you.

"My first thought was, 'Please keep sailing how I set you up'. My second was, 'What am I going to do?' I just wanted to burst into tears. But then the sensible side of me took over. I thought, 'That isn't going to help'. It's not very productive. It took me an hour and a half to get out of the problem. As soon as I got down, I did burst into tears. It did me good. But it was then I realised how vulnerable I actually was. If I couldn't have got down, there was absolutely nothing anybody could have done for me."

That, stresses the 35-year-old, is about as bad as it gets; the time she began seriously to question her own mortality. Yet such recollections do not deter her from the perils which could confront her this year. Her successful completion of the Aviva Challenge in 2006, all 29,100 miles of it, took 178 days. On 9 November Caffari sets out to complete the voyage in reverse, this time racing against the elite in the business in her new £2.5m 60-footer Aviva, when she takes part in the Vendée Globe. It will be somewhat quicker. She expects to be away for three months, unless the seas or elements defeat her first. She can take inspiration from the fact that Ellen MacArthur finished second in the race in 2001.

Before that she participates in the Artemis Transat, a race from Plymouth to Boston in the US, from 11 May, a qualifying event for the Vendée Globe. She is one of three British entrants and one of only two women participating. In the circumnavigational world of Dee Caffari, it is no more than a "a short sprint". That said, she adds: "The weather can be pretty harsh and it's upwind. It's not nice. At least the trip home is downwind, which is where the boats excel. So that makes it worth the pain of getting there".

There is seemingly a masochistic side to her. She readily trades the constant perils and the spartan lifestyle – "no toilet and your best friends are baby wipes, showering in the rain or with buckets of seawater, and freeze-dried food" – to succeed in the challenges she undertakes; ones which yield her a rare view of nature. "An albatross is a stunning sight in the Southern Ocean. If you mix that with an iceberg, you're probably one of the few people who've ever seen that sight," she says. "You get a dolphin with your boat, or a whale, and you almost get blasé about it. It makes you very humble to be in this environment. It's those magical days which compensate for the bad storms and make it worth going back there."

Life has altered radically for Caffari since 2006. For a woman who copes admirably with her own company at sea, she is gregarious, in a delightful jolly-hockey-sticks way, back on land. She was once a PE teacher. Now she does public speaking, frequently to corporate audiences. There are similarities with her former life. "The difference is now that I get to speak to people and the audience actually listens to me, because they want to hear me. At school, I couldn't always guarantee that!"

Caffari, whose extended family on her late father Peter's side is Maltese, is originally from very much landlocked Hertfordshire, and a family whose only contact with water was aboard her father's powerboat during holidays. She did not sail until she went to Leeds University to study sports science. Sailing was part of her course, but sheinsists: "I didn't start out with this great dream to sail round the world. I couldn't even have told you who Chay Blyth or Robin Knox-Johnston were when I was at school. I was more interested in ballet lessons."

Today, as she puts it, "I've earned my street cred amongst sailors. It's just amazing." Her round-the-world feat has won her many distinctions, including an MBE last October. "A lot of people doubted what I wanted to do. Because I was the first woman ever to do it, they would say, 'But you've never even sailed on your own'. I said, 'It can't be that hard'. Also I'm very much 'let me prove that I can't do it before you say I can't. If I can do it, we don't even have to have this conversation'."

Negativity is not part of her psyche. Yet she concedes: "Of course you experience fear, like anyone else. You know what may happen. The weather can be horrendous and you're in the most hostile ocean in the world, two weeks from any rescue. The unknown can be scary. You don't go out to risk your life and be silly about it. But each storm you get a little bit braver. You come through the other side, you think, 'I'm still here, I can survive this'. So the next one can't be too bad."

She adds: "It's strange how the mind works. I can be in tears on the phone [usually to her boyfriend and campaign manager, Harry Spedding, one of a back-up team of nine ], saying, 'This is awful. I haven't slept. I'm really scared'. And two days later I can be sailing in a glorious sunset, the boat's moving like a dream and it's like, 'This is brilliant. You should be here'. This emotional roller-coaster is so severe. But your mind has an amazing ability to put the bad stuff in a box, and you put it away. You forget it almost instantly. If you dwell in all the negative all the time, life's pretty miserable."

How do the couple hold together a relationship when they are apart for so much of the time? "It's actually probably what's kept us together," Caffari says wryly. "We don't get to that bickering stage. We get used to living on our own, and then have to get used to coming together again. We're both very independent and, if anything, we have to allow ourselves back into each other's lives. But it helps that he understands what I'm doing, and why. Basically I go away all the time. Anyone else would probably be thinking that he was doing something wrong." Spedding knows only too well what drives this remarkable woman.