Billy's incredible... we're all so proud of him, says dad

Although the surgery was successful, he had to be monitored closely by doctors well into his teenage years.

But 18 years on from the life-saving operation, the Hill Head teenager has defied expectations by representing the UK at the Youth Sailing World Championships in China.

After coming 20th in the competition earlier this month, Billy and his family praised the ‘amazing work’ done by staff at Evelina London Children’s Hospital, where he underwent surgery.

Billy said: ‘I am very proud to have represented the UK at the Youth Sailing World Championships – it’s a dream come true.

‘It’s taken a lot of hard work to get to this point, and I wouldn’t have been able to do it without the help and support of my parents and the great team at the hospital.’

The youngster is currently studying for his A-levels, and as well as hoping to start university next year he also wants to compete at the 2024 Olympics.

His father Andre Ozanne said: ‘Billy is an incredible boy and we are very proud of him.

‘To see him develop into a grown man who has achieved such great things in a short amount of time has been incredible, and those dark days are long gone and forgotten about, with only his scar to tell the story.

‘We are forever grateful to the doctors at Evelina London who have helped Billy to get to where he is today. Without their amazing work he would not be here.’

Dr Owen Miller, consultant in paediatric cardiology at the hospital, followed Billy as an outpatient for most of his life and has kept in contact with the Vennis-Ozanne family as the teenager’s sailing career developed.

He said: ‘Billy was born with a heart condition that meant his main cardiac arteries were connected from the wrong side of the heart.

‘This meant that Billy would have been a “blue baby” with dangerously low oxygen levels.

‘If left untreated this could have been fatal, and he had to undergo an “arterial switch” procedure at just 14 days old to reconnect the arteries the right way round.’

Billy’s love for sailing developed when his family moved from London to Hill Head in 2005, and six years later he competed in his first national under 13s competition on Hayling Island.

Before taking part he had to undergo a precautionary MRI scan and fitness test at the hospital.