"He was absolutely devastated. We were able to assure his mate that it wasn't his fault, it was just an accident."
A search was started for him late Saturday afternoon when he went missing.
After hearing about the missing man, local boaties rushed to help.
Outback Helicopters owner Jason Pendergrast found the body in about a foot of water.
After sighting Malcolm, Mr Pendergrast alerted the nearest boat, and then landed his helicopter on nearby rocks to help bring the man into shore.
He said: "His mate came running over to help drag him to shore.
"I turned him over but he was already dead."
When asked if there was any attempt at resuscitation, Mr Pendergrast said: "It was too late for any of that."
"It sounds like the three of them went diving and one didn't come back," he said.
Akitio Volunteer Fire Service chief officer Murray de Admin said they received a callout at about 4.30pm, but arrived too late.
He said other local respondents had done a great job.
"When the siren went up there were locals already in the water.
"They had their boats in the water straight away ... when he went missing people ran to find help."
Malcolm was going to turn 38 this week.
He will be remembered as a man who loved the sea, had a heart of gold, and was "an absolutely brilliant dad".
His father said their close-knit family was working together to get through.
"As a dad, you never think your children will go before you.
"We have to take each day as it comes."
Mr Cameron said his son was "an absolutely brilliant dad".
"His boys, and his partner Sarah were everything to him, they were his life. They all absolutely adored each other.
"He was a character, he was never worried about what people thought of him - as a son he's been a credit to my wife and myself."
