It may be wise to write your own obituary, but not if it lands you out alone in the middle of the Pacific Ocean. Yet it was in response to this self-help exercise that Roz Savage decided that it was time to change direction.

The Cheshire-born Oxford law graduate had already done a fair bit of thinking about that change before she sat at her dining room table. One version of her life seemed impressive enough: City of London management consultant, in her early 30s, married to a successful husband. It was the life she says she had longed for as a teenager.

Yet it didn’t quite fit how she wanted to be remembered. She credits a visit to Sligo, preceded by a move to New York to work as a photographer and three months in Peru, with her decision to leave it all behind.

Some years later she was bouncing around in a 23ft boat somewhere between California and New Guinea, as she achieved her ambition to become the first woman to row three oceans and raise awareness about threats to the planet.

“I had rowed at university,”she laughs as she recalls that “happy delusional” state in which she believed that wearing an Oxford singlet gave her the qualifications to undertake the challenge. “As I was to find out, that ability counted for nothing out on the ocean. It’s more about the ability to stay alive.”

Managing logistics, and having the mental strength for solo voyaging, were other prerequisites. “I don’t believe I had all those qualities,”she says. “I am naturally quite a reflective person, and so when I was struggling psychologically, such as out in the middle of the Atlantic, my mood was not helped by my GPS Chartplotter.”

She completed the solo passage from the Canary Islands to Antigua in 103 days between 2005-2006. Oars were broken in storms before she had got halfway, and she also lost or damaged her camping stove, stereo and cockpit navigation instruments.

“Frustration and boredom were most challenging, particularly on the Atlantic, and when the stereo broke very early on, and I only had my own thoughts to entertain me, it was a bit like Vipassana meditation on steroids!”

The Pacific, 8,000 miles across, was completed in three stages from 2008 to 2010. “I listened to audiobooks, so I felt a bit like taking the easy way out,” she says.

She encountered 8m high waves, capsized three times in 24 hours and suffered dehydration. Yet she found the shorter Atlantic tougher, because it was her first ocean crossing, she was in a race and it was a “very introspective experience”.

In all, she has rowed over 15,000 miles, taking an estimated five million oarstrokes. She has become a fellow of the Royal Geographical Society, international fellow of the Explorers' Club, and was named a 2010 Adventurer of the Year by National Geographic magazine.

She is also a UN Climate Hero and speaks regularly about climate issues.

“When you are out there, you really do realise how the health of our planet depends on the health of our oceans, which we have completely over-exploited,”she says.

Not surprisingly, she is often asked if she has read Life of Pi . "Yes, twice. It made me very glad that the only animals I have on my boat are of the stuffed, squishy variety,"she says. "But also a very interesting commentary on how we all create our own reality. Especially at sea."

Stop Drifting, Start Rowing: One Woman's Search for Happiness and Meaning Alone on the Pacific is due to be published in October. Savage speaks at the West Cork Literary Festival in Bantry's Maritime Hotel today at 3.30pm(€18) and will have a "coffee and chat" tomorrow in Bantry House tearoom at 10am (€8).