Kieran said: "I went off the rails from the age of 16. It's only been the last six months that I've pulled myself together.
"I did a lot of Class A drugs, stole from people, and committed crimes to feed my habit of coke and Ecstasy.
"I had a lot of emotions under the surface, and it was a confusing and dark time."
He added: "My grandparents asked me to leave because I was coming in drunk, being aggressive and disrespectful.
"I should have been making them proud of me.
"They had given up their retirement to look after me, and I should have given them much more respect."
It was while living at a hostel in Newcastle late last year that Kieran was encouraged to get involved with the Fairbridge programme, which supports young sailors, and is part of The Prince's Trust charity.
This summer, he sailed from Waterford in the Republic of Ireland to Greenock in Scotland, as a trainee on board the Spirit of Fairbridge, during the Tall Ships Races.
He learned to take responsibility for the running of a ship, from cooking to navigating, keeping watch, and steering.
He explained: "I loved it straight away and it reminded me of the kid I was before I went off the rails.
"It gave me confidence and I enjoyed learning new skills, and the teamwork."
Kieran, who has just moved into a council house in Newcastle, has also been able to rekindle his relationship with his grandparents, Stan and Carrie Maxwell, who now live in sheltered accommodation in Simonside.
Mrs Maxwell, 76, said: "We are very proud of him. This last few months he has really turned himself around.
"We always knew he had it in him.
"He has leadership qualities, and we hope he can make something of himself now."
Kieran is hoping to join the Army, and is considering his career options.
For winning the Torbay Cup, Kieran was also awarded 500 euros from the charity Sail Training International, to go towards another voyage.
(First published 12th October 2011 by Joseph Tulip, The Shields Gazette)