The screams of his terrified child from an air pocket under a capsized boat are likely to stay imprinted on a Lower Hutt dad’s mind for some time.

The frantic moments after a rogue wave overturned their small boat off the coast of Eastbourne last weekend are harrowing to recall: a fumbling grab for his child, his desperate efforts to keep the boat tilted up, and his exhaustion as he collapsed on the shore, his son alive.

“Any other kid that hasn’t had any sea experience probably would have died that day,” he told the Herald.

They were travelling back from a diving excursion on their 16-foot boat when waves crashed over the motor and began filling the boat with water.

The man tried to turn the boat but seconds later the sea had taken over, and the vessel was upside down with the boy trapped underneath.

“My mind was going a thousand miles an hour, it’s pretty hard to explain, eh,” the father said.

“All those bad thoughts are just coming into your mind straight away.

“I was screaming and he was screaming back, so I knew he was still there. We reacted by going to the front of the boat and tilting it up to keep that air pocket. We told him to stay there and hang in there.

 “He was screaming, like ‘Dad, Dad, help me Dad.’ I had to just try and keep my composure and not give up.”

A couple on the beach at Lowry Bay rushed to alert police then came in to help pull the boat to shore.

The boy has experience on the water with his father. Photo / Supplied

“They started to pull it in while me and my mate were trying to keep my son up in the air. We weren’t even touching the ground at the time, we were just kicking water.”

Finally they reached the shore and as a police officer from the Maritime Unit jumped in to help, they were able to get the boy out from under the boat.

“I collapsed on the sand, I just dropped myself to the ground I was so exhausted.”

Another couple on the beach took his son away to get changed out of his wet clothes and fed the boy biscuits and water while his father recovered.

The father has been taking his son on diving trips and had been teaching him all about water safety, which he believes helped save the boy’s life.

“He’s used to being out in the deeper water with me on my boat ... he follows instructions very well when it comes to water.”

The man tells his children “the water can take you away at any time”.

The man told his son he was “very brave” and he was proud of him for keeping his head and following instructions.

His son was wearing a lifejacket and they had all their safety measures in place.

The boy was now “in good spirits”.

“He’s great, he’s doing better than I am. He just said he won’t jump on my boat ever again, he’ll jump on my mate’s boat but not mine.

“He lives to tell the story.”

The man wanted to thank the strangers on the beach who had come to help with the rescue and who had taken care of his boy afterwards. He also wanted to thank the police for their help.

The Maritime Unit’s Sergeant Richard Kennedy said that day’s rescue was a reminder of why police “do what we do”.

He said the boy was in the water but the buoyancy of his lifejacket pushed him hard up against the hull of the boat, into the pocket of air.

“When a boat’s capsized like that, often ... it forms a suction on the surface of the water.

“I’ve been in this unit for 15 years and it’s one of those days where goosebumps turn up on the back of your neck - and I didn’t even do the job,” he said.

“It’s not uncommon for people to get trapped inside the boat [and drown].”

It would have been a frightening few minutes for the boy waiting to be rescued, he said.

“It was a few minutes, it wasn’t seconds, and that would have been a long few minutes that he was trapped in there.”

The incident showed how much having a lifejacket on could help keep someone alive.

Kennedy wanted to remind water users to practise water safety as this group had done.

“We’re talking about things like keeping an eye on children when they’re on the water, putting a lifejacket on, knowing the marine weather forecast, avoiding alcohol while doing water activities, keeping within your limits and generally treating water safety as a priority.”