When Tom Gregory was only 11 he swam across the English Channel. This is his story...
On September 6 1988, Tom stood in his swimming trunks, greased up, on the tip of France ready to face the gruelling 32-mile swim back home.
He was stood in the dark on a beach at five in the morning with waves lapping over his calves.
In front of him was the Black Sea and then "a little smudge of light" which he assumed was Dover.
It was so dark that measures were put into place not to lose him.
Becoming the youngest person ever to swim the English Channel, shaped the rest of Tom's life.
As a former Royal Anglian Regiment Officer, Tom served in both Iraq and Afghanistan.
"There has to be a thread doesn't there of spending time in challenging environments, operating as part of a team, training for something potentially remarkable."
Tom was wearing only his favourite swimming trunks and a pair of goggles when he took on the challenge.
He followed a boat and when it got too deep, he started to swim. He didn't stop for 12 hours.
Tom says the years of training and resilience required for this swim helped him become a soldier.
"That good old thing, enthusiasm. I just loved doing it. Much in the same way as I loved being a soldier actually."
Even though the swim took place 30 years ago, Tom remembers it very clearly.
His new book 'A Boy In The Water' tells the story of his friendship with his coach John Bullet who mentored Tom and whose actions would shape the rest of his life.
"He built that swimming club from nothing and things that people who have worn a uniform will understand, a sense of shared identity, working towards a common goal, teamwork and looking out for other people.
Tom now works for an accountancy firm and wrote the book on his commute to work over nine months.
He has already been approached by a well known Hollywood actor about the possibility of turning the story into a movie.
You can watch Tom's chat with Forces Radio BFBS presenters Hatch and Geere in full below: