Wife pays tribute to hero who died saving child at City Beach

The grieving wife of a man who drowned trying to save a stranger's child on a NSW beach has paid tribute to her "darling husband and best friend".

Shaun Oliver, 32, was hailed a hero after diving into rough seas to rescue a 12-year-old child on Wollongong's City Beach on Sunday.

A local surfer ultimately helped the child to shore as Mr Oliver, a father of three, was swept out to sea.

A devastated Carla Oliver, who started a relationship Mr Oliver in early highschool, posted a tribute to her husband on Facebook on Tuesday.

"My heart is torn into a thousand pieces," she wrote.

"I am so proud of you, but so so heartbroken to be without you forever.

"You were away for work and kids were counting down the days until you were home.... never in my wildest dreams would we see this coming and now we all miss you so much more than I could ever imagine."

Mr Oliver, from Craigeburn, had been working in NSW for a week and was due to fly back to Victoria on Monday.

City Beach had been closed due to treacherous conditions when Mr Oliver decided to take a walk about 4.30pm and saw four children struggling in the choppy surf.

A capable swimmer and keen sportsman, Mr Oliver leapt into the water, but was overcome by waves described by surfer Tom Parkinson as "brutal".

Mr Parkinson helped the boy to shore, then returned for Mr Oliver. It was too late.

Mr Parkinson said the water was "big white wash, big rips. I couldn't believe anyone would go out there".

Police officers performed CPR on Mr Oliver on the beach. He died later in Wollongong Hospital.

Mr Parkinson praised Mr Oliver's bravery: "He didn't have a board and he still paddled out, so he did the far greater thing, he's the real hero".

Mr Oliver was a loving father of three children aged three to seven. He had been with his wife, Carla, since high school.

"We are lost without you," she wrote on Tuesday.

"May you fly high and Rest in Peace, I know you and Dad are forever watching over us."

A GoFundMe page, set up by Mr Oliver's cousin Nathanael Oliver, had raised $106,200 by Tuesday night.

It aims to raise $500,000 to support Mr Oliver's young family, for which he was the sole income earner.