It was for them that Joseph trimmed the lawn to perfection, planted a garden, erected a swing and rode a pushbike to work each day to save money to build their dream home.

But last night Monique, 17, Elise, 14, and Nicholas, 9, from Orangeville in Sydney's south-west, were orphans.

They watched helpless from South Ballina beach on Tuesday night as their parents drowned in a desperate struggle with a strong rip.

Police said Mrs Sherry, a school teacher, had swum out to help her children on the unpatrolled North Coast beach at 6.30pm, but when she could not get back her husband went to her aid.

As his parents fought against the current, Nicholas ran to the nearby caravan park, where they were staying, to raise the alarm.

Elise used a mobile phone to call triple-0 from the beach, but by the time park residents and paramedics arrived, the surf was carrying Mr Sherry's body in to shore.

The local rescue helicopter and a Ballina Jetboat Rescue crew went in search of Mrs Sherry. Her body was only 50 metres from land when they found her.

The Jet Boat rescuers who retrieved her body said they had struggled to keep their heads above water.

''The surge of the water was really strong; it wasn't easy pulling her in - there was a lot of water moving," said Joe O'Connor.

Last night the couple's children, the eldest of whom is intellectually disabled, were in the care of relatives on the North Coast.

Neighbours in their semi-rural Orangeville street were shocked. ''This was their big holiday. They obviously couldn't afford many, so this was the big one,'' Marilyn Searle said.

''They were genuine Australian battlers that wanted the best for their family. Why should this happen to people who create a good home for their children and then die in the attempt to try and save them?''

Ms Searle said Mr Sherry, a TAFE teacher, worked tirelessly for his young family. ''It was the self-sacrifice; everything he did was for the betterment of his family,'' she said. ''It was total self-sacrifice to the end.''