Waves smacked the side of the 45ft Caledonian Hero as the yacht pushed on through the Kyles of Bute, the wind whipping at her sails and Ewan Brown clinging to her deck.

The water was inches away. It was terrifying, exhilarating and Ewan, who battles through each day not knowing if he will ever beat cancer, felt alive.

“The boat feels like it’s keeling over. It’s half terrifying, half amazing. You’re on the edge with your head around a foot away from the water,” he says. “You’re screaming through it with the adrenalin kicking in.”

He’d been encouraged to join a four day sailing trip organised by the Ellen MacArthur Cancer Trust. They set off from Largs throughout summer, a mini flotilla of yachts manned by some experienced hands and a group of people like him, whose young lives have been cruelly blighted by disease.

“So many people said it was life changing,” he recalls. “I thought ‘Okay, it’ll be good, but not that good’.

“By the time I finished I was that person saying it was a life changing experience.”

Ewan, 25, is among over 200 young people so far this year who escaped the challenges of living with their illness while on board a yacht somewhere in the waters between Largs and Port Bannatyne; who discovered – possibly while battling a headwind on their way past seals or porpoises off Millport, or as the sun set over Arran – that there were other people who also know what it’s like to walk every day in cancer’s shadow.

In Ewan’s case, skin cancer emerged three years ago. What started as a stage one melanoma on his face that seemed to have been dealt with, re-emerged in lymph nodes in his neck. He received the ‘all-clear’ after surgery, relaxed a little for a week, and then it was back.

“My future is up in the air,” says Ewan, from Edinburgh. “I don’t know if I will survive. It’s hard to talk about that with someone who has never had to think about that before. They don’t know what to say.

“The sailing is an added perk,” he admits. “Meeting people who have been through the same, some less, some worse or different, and to be able to talk about things that I’ve never been able to talk about to anyone else, that is the main thing.”

The crippling worry and feelings of worthlessness that led to him dropping out of university have been replaced with new confidence. Now studying electrics and electronics at Strathclyde, he says it is down to sailing with the Trust.

"It truly changed my life from one I hated to one that I love," he adds.

The Trust is now preparing for its next outings from Largs, where it has had a base since 2013 and which is home to the Caledonian Hero and its other yacht, Moonspray, both bought using funds from the Peoples Postcode Lottery.

The free outings – which still have places available - will take it a step closer to breaking its own record for the number of eight to 24-year-olds it has taken out on the west coast waters in a single season.

Kerry McMillan, operations manager at Trust’s base at Largs Yacht Haven, sees the life-changing impact each trip can have and says it makes her feel humble every time. “There’s something magical about putting people on a boat. It creates a sense of community,” she says.

The Trust uses its own yachts and charters others to take young people on their first trip sail from Largs to Port Bannatyne, up the East Kyles and on to Kip Marina. Most come back for more - second time trips go deeper, to the Holy Loch, Rhu, Tarbet and Loch Fyne. Some notch up several trips and go on to become volunteers, passing their experiences to a new generation.

“The young people get to know each other, they sail, play old fashioned board games, have barbecues, go crabbing and build relationships They get support from other young people who have been through the same thing.

“It’s the opportunity for quality time with others who know what they have been through, who totally accept whatever issues they may have, and they don’t have to explain why they take medicine, why they might walk a bit differently.

“They can be themselves.”

The trips were devised by lone round the world yachtswoman Dame Ellen MacArthur, who launched the Trust in 2003 after being inspired by a French charity which used sailing to help children cope with the aftermath of their condition.

She describes the opening of the Largs base in 2013 as a “major milestone” in the Trust's work.

“Somehow on these trips there's some magic that happens. It's hard to explain and you have to live it and breathe it to understand it, but everyone lets their guard down, everybody gets on, there's a real family atmosphere.

“It's not really the sailing or the water, but the being on a boat which creates that and it's the environment being on a group of boats creates.

“We find a huge transformation in many young people the first time they come with us, and we often have letters from parents saying 'thank you for giving us our son or daughter back'."

She says the Trust’s achievements are easily measured: “Many, many, many smiles and not just from the young people but from their parents as well.

“The goal of the Trust is helping young people in recovery from cancer and leukaemia and seeing those smiles and that confidence build is what it's all about.”

The next trip will set off for another voyage around the Firth of Clyde in a fortnight’s time. The charity is urging 18-24 year olds who have now finished cancer treatment to take part.