A West Australian man has been hailed a hero after he pulled a man and his six-year-old son from turbulent surf at a Melbourne beach.

Ben Robertson had just gotten out of his car during a visit to Williamstown beach, south-west of the Melbourne CBD, when he spotted two people who appeared to be struggling in choppy waves.

“I had only got to the beach about 30 seconds beforehand and my wife and I were just walking along and heard a whole bunch of people calling for help,” Mr Robertson told 3AW on Monday morning.

“They were in a fair bit of strife.”

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Krissi Kirk said she, her husband Richard, and their two children were at the beach on Friday evening when six-year-old Noah was swept up in unexpectedly strong waves.

Richard ran into the surf to rescue Noah, but Ms Kirk said they were caught in a riptide.

“We were just at the beach, Noah was exploring and having fun. There was a long sandbar so it was okay for him to be a little away from us, we thought,” she said.

“Then the sandbar came to an end and Noah was out of his depth, the water just seemed to turn and got a bit choppy, my husband got to him and kept him okay and then it just seemed to get really out-of-control.

“My husband was having trouble staying above water, my son was having a lot of trouble and was clinging on to my husband.”

Enter 26-year-old Robertson, who Ms Kirk referred to as ‘amazing Ben’.

He dove into the water, with three men in wetsuits following him in soon after, to swim out to the pair.

Noah was the first to be saved, and was handed to his frantic mother, who had remained on the beach with their one-year-old child.

It took all four men to bring Richard in.

Ms Kirk said both were doing well, although her husband was still recovering from the ordeal.

Mr Robertson said he had never been to Williamstown Beach before Friday.

Although the choppy water provoked the ordeal, it was also what drew in their rescuers.

“(It was) the only reason I got out of my car. I had never been to Williamstown Beach before and I was quite surprised by how rough it was, I always thought it was a nice calm beach,” the 26-year-old said.

The pair got in contact after Ms Kirk posted a thank-you post to Facebook.

The Williamstown Swimming and Life Saving Club have been contacted for comment.