Caroline Wakefield died within days of contracting water-borne polio in 1957
Tony and Daphne Wakefield transformed what was a deep personal loss into a lasting public legacy.
After their six-year-old daughter, Caroline, died of polio as a result of swimming in sewage-contaminated water off Gosport in the summer of 1957, the bereaved couple decided the British public needed to be alerted to the dangers that lurked by the seaside.
The result was their meticulously-researched Golden List of Beaches, which has since evolved into the Good Beach Guide.
Today, the guide is a seaside bible.
Published online by the Marine Conservation Society and reissued every May, the site is visited by more than 500,000 people annually in search of information about clean, safe British beaches.
Chris Wakefield, Caroline's brother, who was 13 when his little sister died, said his parents took comfort in their campaign for cleaner beaches - a campaign that still resonates today and that helped push for the adoption of the European bathing water directives.
How one tragedy made a difference
"My father, I believe, was very happy in the way that he was able to see the European water directives implemented in this country. I think that brought comfort to him," he told the BBC of his late parents' efforts.
Caroline contracted water-borne polio just 10 days after her mother took her swimming during the summer of 1957. She died within days of falling ill.
Her brother had been visiting relatives in London during the warm spell early that summer and was not in the polluted water.
"My parents were particularly incensed that there had been so many statements from the authorities saying all was well," Mr Wakefield remembered of the medical advice of the day that said salt water was sufficient to kill off sewage bacteria and that the beaches were safe for swimming.
Local councils and the tourism industry at the time concurred with the prevailing wisdom, eager to avoid large infrastructure bills or drive away potential business from the seaside resort towns with any talk of dirty, dangerous water.
In theory, the Victorian sewer works were designed to pipe raw sewage from holding tanks into the sea, timed with the tides in order to ensure that waste was flushed away from the shorelines and dispersed.
Chris Wakefield was 13 when his little sister died of polio
But a growing population in the early to mid-20th century meant that the holding tanks were almost constantly overflowing - causing raw sewage to be discharged on a near-continuous basis.
In the months after they lost their only daughter, the Wakefields formed the Coastal Anti-Pollution League, with an aim of warning bathers away from beaches that were close to sewage pipes.
Chris Wakefield recalled helping his father, Tony, to compile the information for the guide.
They wrote to every local council in England and Wales and asked them to identify the location of the thousands of sewage overflow pipes.
"I vividly remember helping my father go through every ordinance survey map for the entire coastline and plotting where the sewage pipes were located," Mr Wakefield said. "You can imagine the job that was in those days - no internet then."
Daphne Wakefield took her story of grief public on Woman's Hour and the family took part in a 1957 documentary for BBC's Panorama on raw sewage contamination in order to raise awareness.
Her son, now 66, said his parents, like others who had suffered tragedy in their lives, channelled it into helping others.
"I believe my mother wanted to warn other parents, to help keep their children safe so that such a tragedy would not befall them."
Thomas Bell of the Marine Conservation Society (MCS), called the Wakefields' dedication "an astonishing legacy".
I think the benefit of what they did, in terms of public health, is enormous
Thomas Bell Marine Conservation Society
"What the Wakefields did was shine a spotlight on what was happening on our beaches and to give it a public profile," he said.
"They did that by saying 'we are just private people and this is what we know can happen and we think you should know too' and their reach was remarkable."
Mr Bell said he believed their campaign was a key component - along with European legislation and gradually changing public attitudes - to pushing government and the water industry to spend a combined £20bn on sewage treatment and clean-up.
They worked tirelessly through the 1960s and 70s, and only began to see real improvement in the late 70s and into the 1980s.
"I think the benefit of what they did, in terms of public health, is enormous," he said. "They were environmental campaigners before environmental campaigning existed."
Chris Wakefield said the adoption of the European regulations on water quality signalled to his father that it was time to wind down his Coastal Anti-Pollution League charity in the late 1980s.
He searched for a suitable home for its resources, including the Guide to Golden Beaches and decided to give over the assets of his charity to the Marine Conservation Society in 1987.
"I think he felt very content in that he had done a good job and he was able to close down his charity and pass on the funds and then have it be taken in by the MCS."
It is an inheritance that the MCS's Thomas Bell says is still contributing to Britain's environmental movement.
"What they started is still relevant 50 years later," he said. "The Wakefields shifted the goalposts of what was acceptable and kicked off all that has happened since."
Panorama: Britain's Dirty Beaches, BBC One, Monday, 7 September at 8.30pm.
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