A former heroin addict who fought back from the brink of suicide to become an endurance athlete is hoping his latest charity challenge will raise crucial cash for good causes in his local community.
Gavan Hennigan, 35, of Galway, spent the early 2000s addicted to heroin and alcohol, living in squalor in east London.
At his lowest, he attempted suicide as he battled to deal with being gay.
But he turned his life around and now travels the world taking on extreme and endurance challenges - including the Talisker Whisky Atlantic Challenge, dubbed the world's toughest rowing race, which starts on Wednesday in the Canary Islands.
Speaking of the battle to turn his life around, the teetotal athlete told the Press Association: "I had a really tough time in my late teens and early 20s. I was heavily addicted to drugs and alcohol. At the end of it, I was living in a squat in east London, in a bedroom with no curtains, just black bags and a mattress on the ground.
"I would wake up in the morning and smoke heroin and then go back to sleep. It was a pretty dark place. I had a suicide attempt at 21 not long after coming out of rehab - I just couldn't deal with the fact I was gay.
"I had a lot of personal struggles. I feel like having come back from the brink, that dark place in my mind, I don't feel like something like this challenge could faze me too much - this is just for fun."
The challenge will see Mr Hennigan and 28 other competitors row from La Gomera, almost 5,000km (3,000 miles) across the Atlantic Ocean to Antigua in the Caribbean.
He will be joined on board by 90 days of ration packs and boil-in-the-bag food and a satellite phone to keep in touch with loved ones and race control.
Mr Hennigan said: "It really appealed to me because it is the ultimate endurance challenge. I've done mountaineering and ultra running. This is a whole other level of logistics and uncontrollables and variables.
"I've worked for 10 years as a saturation diver on the oil rigs. I spend up 40 days in a saturation diving chamber, going to depths of 200 metres to do heavy construction on the oil platforms, so my job lends itself to a lot of this endurance stuff.
"I've forged very good resilience from working in such extreme environments. I gradually started doing more and more adventures out of work.
"I've adventured to all seven continents, from completing two of the longest Winter Ultras in the world to crossing a frozen lake in Siberia on foot. I've worked in extreme water depths and climbed high-altitude peaks in the Himalayas, but now I'm ready to take the ocean on in the Talisker Whisky Atlantic Challenge, the world's toughest row.
Sean McGowan, the only Irishman to have previously completed the challenge, did so in 118 days - a feat Mr Hennigan is determined to beat.
He said: "Sean had a lot of things go wrong so he's confident I will at least halve his record.
"But it's real out there. There is a lot of stuff that can go wrong. Hopefully, we can deal with every eventuality. There is generally a solution for most things - baring a blue whale coming and breaking the boat in two.
"Most people think this is completely crazy and I did myself when I first heard about it."
He will be raising money for Jigsaw Galway and Cancer Care West.