The family of an “extraordinary” young man who died after his heart stopped while swimming hope some solace can come from his tragic death.

Super-fit Dominic Hamlyn, 24, was doing lengths underwater during a family birthday party at his home near Canterbury when he suffered a sudden cardiac arrest.

Frantic friends immediately pulled his motionless body from the pool and rushed to fetch his father - leading neurosurgeon Peter Hamlyn - who started CPR.

But despite his determined attempts, the rapid arrival of paramedics and the efforts of specialist doctors who worked on him throughout day, he died in hospital 15 hours later.

An inquest on Thursday determined the former King’s School pupil had suffered a cardiac arrest from a previously unsuspected heart condition.

Unconnected with the swimming, medical experts agreed it could have occurred at any time or place.

Drowning had been discounted as a cause by the pathologist and other experts because of how quickly Dominic was pulled from the water, as was so-called ‘shallow water blackout’, an incredibly rare occurrence in which a person runs out of oxygen.

The Cambridge graduate’s father said: “Blessed in our lives, our luck ran out that night.”

The inquest at Maidstone’s Archbishop’s Palace was told the tragedy occurred during the 21st birthday celebrations of Dominic’s younger brother, Benedict, at the family home in Crundale.

Following a gathering described as “convivial and well-behaved”, at which Dominic had delivered an “irreverent and entertaining” speech about his little brother, he went for a swim with friends, as he often had.

It is then tragedy struck, with a super-fit athlete - who excelled in rugby, rowing and cricket - losing his life to an undetected condition of which his father says there needs to be more awareness.

Mr Hamlyn, a sports expert who saved the life of boxer Michael Watson when he was injured during a world title fight with Chris Eubank in 1991, is calling for more education within existing services on the potential life-saving opportunities.

“Such cardiac arrests in young people are not rare, and tragically they are usually lethal,” he said.

“However, outside a small group of specialists there is widespread ignorance of the condition.

“Why does all this matter? It matters because the lack of awareness and medical imprecision is killing young people every day in Britain.

“As a family, our only solace is to try to make sure others do not die needlessly, and the only hope for potential victims is to pick up the underlying condition before it strikes.”

Data from coroners’ death certificates shows that “at least 12 young people die of cardiac arrest each week in the UK”, with Mr Hamlyn saying this is likely to be a “gross underestimate”.

“As a result, victims’ families will continue to go unscreened and readily treatable warning signs missed,” he said.

“Families such as ours, who have lost a loved one to a young cardiac death, must undergo specialist screening to see if they have one of the inherited risk factors.

“An apparent drowning or road accident may mask the cardiac arrest that is the true cause of death.

“More specifically, pathologists need to look for cardiac abnormalities when investigating young deaths. Crucial tests that can turn up otherwise unsuspected cardiac problems are not part of a routine inquest but must be carried out.

“Likewise, readily treatable warning signs must not be missed. Any young, fit person experiencing faints or blackouts should be screened by a specialist unit.”

Mr Hamlyn wants his son’s legacy to not be that of a family immersed in grief, but one that brings awareness and change.

“The loss for us is profound and life-changing,” he said. “No words can describe the scope and scale of it.

“Along with my wife and Dominic’s two brothers, we each feel a part of us died with him that day.

“It is my fervent hope that lives will be saved in his name. It is our only comfort now.”

Mr Hamlyn's brothers Gabriel and Benedict are also raising awareness of the condition.

For information on CRY - Cardiac Risk in the Young, visit cry@c-r-y.org.uk or call 01737 363222.

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