It is 6am in the Southern Atlantic. Sam Davies is sitting on a bench in the tiny cabin of her boat. To her right is a blue cup containing her breakfast: porridge oats and powdered milk mixed with desalinated sea water. To her left, her onboard computer is slowly, painstakingly downloading the latest weather information and feeding it into her navigational software.

She walks outside and looks around. The bright blue waters, shimmering in the morning sunshine, extend as far as the eye can see. Davies smiles to herself.

She has not seen another human being for weeks, her only tenuous contact with another member of the species coming when a British fighter plane looped the loop as she skirted the Falkland Islands. Such is the echoing sense of isolation that Davies has started talking to her boat, but she is reassured about her sanity because it has not yet started talking back.

She is dog-tired, her bones aching through her waterproofs, but undeterred. She feels an enduring sense of satisfaction, bordering on intoxication, at being a participant in a race that has taught her new and vital things about her inner resolve. She knows that there will be no tears, no regrets, of the kind that have afflicted so many other competitors.

She smiles again as she braces her tiny body for the rigours of a new day.

Davies, 34, is a remarkable woman. She is remarkable not just because she has competed in the fearsome Vendée Globe round-the-world yacht race; not just because she finished in fourth place above all other Britons and ahead of 25 other competitors; not just because she achieved all this in a boat that, by all accounts, was less advanced than those of her competitors. She is also remarkable because on Wednesday afternoon, in a small office in Wapping, East London, she spoke to a hack contemptuous of solo yachting and seduced him.

Seduced him with her descriptions of its kaleidoscopic challenges and visceral dangers; seduced him with the bravery and tenacity that she wears so lightly. But, most importantly of all, she seduced him by conveying the magic and existential meaning of an extraordinary sport.

These are Davies's musings, e-mailed to this newspaper from her onboard computer, as she reached the final stages of her 96-day odyssey: “There are so many magical moments that are impossible to describe. The amazing golden sunsets, the dolphins playing in Roxy's wake, the icebergs, the pitch-black stormy nights, the fire of the moonrise, and a beautiful dawn seen through stinging eyes are all memories I will cherish forever.”

Her writing is imbued with haunting power, but it is her spoken words that take on an irresistible urgency. “More people have travelled to outer space than have competed in the Vendée Globe,” she says, blue eyes sparkling. “When you are out there, all alone, it is like being in another universe; it is as if you are coming face to face with a new vision of yourself. It is scary and challenging, but at the same time totally captivating.

“You cannot experience what I have experienced by going out for a single day and then returning to dry land for a hot meal and shower. You cannot experience it in an aeroplane or on a boat with lots of other crew members. You may be able to get to the same places, but you cannot know what it is like to be there in total solitude. The only way you can ever experience the surrealism of being alone in the middle of an unimaginably large ocean is to sail out there yourself. Who would not want to do that?”

Davies seems oblivious to the cumulative rigours of her expedition, despite finishing only a matter of days ago. A slip of a girl, she had to endure sleep deprivation, soul-sapping hardship day after day, and the ever-present possibility of extreme physical danger, but she talks as if the whole thing was an unmitigated privilege and seems almost regretful at being back on terra firma.

Her toilet on board was a blue bucket, her cuisine a series of freeze-dried ready meals, her only company nine-metre waves dashing against the bow. But there is more to successful yachtsmanship than a willing streak of masochism. “You have to be a meteorologist, computer whizz, hydraulic engineer, electrician, engine specialist, sail-maker, cooker, cleaner and editor,” she says. “Oh, and you also need a little sprinkling of madness.”

Davies's motivation, needless to say, is vocational. “You do not go into sailing for the money,” she says. “I earn enough to be able to train professionally and pay the mortgage [the home she shares with her boyfriend is in La Forêt in France, dubbed the “Valley of the Madmen” because of the number of solo sailors who live there]. If I ever found that money had become a motivating factor, I would leave the sport.

“But I don't think that will happen. There are so many more wondrous adventures to embark upon. The dream is to build my own boat for the next Vendée Globe in 2012 [it is a quadrennial event]. The build-up is as intense and requires as much dedication as training for the Olympics. The difference, of course, is that solo sailing is so much more enticing. Wouldn't you like to join me out on a boat sometime in the middle of nowhere?”

I never thought I would hear myself saying this, but I would, Sam, I would.