Mr Willcox marked the 69th anniversary of the Australian Army accident on Wednesday.

"I was there that day we went out into the Bight," said Mr Willcox, now aged 89.

"I don't want this to be forgotten."

The training exercise, codenamed Operational Seagull, involved about 20 amphibious craft travelling from Horseshoe Beach in Newcastle towards Port Stephens for a night-landing exercise.

The exercise involved amphibious ducks and tanks with 184 men, stationed at Camp Shortland near Nobbys.

Mr Willcox was in a supply duck on that fateful night.

"We went out through the heads and across Stockton Bight at about 2am," he said.

When they departed, the "seas were flat and it was quite good". The weather was forecast to be fine.

"But once we got into the Bight, the weather changed. The sea came up and swamped a lot of the amphibious craft."

Waves up to six metres hit the craft at about 3am.

About 100 men had to abandon ship or were thrown overboard, some two miles from shore.

Some held hands in a circle in the sea to stay together and were picked up after half an hour, while the current carried others towards the shore.

Some men ended up in the water closer to the beach, where their craft were swamped by the breakers.

Three men drowned - Trooper Michael Mornement, 20, of Mayfield, Corporal Noel Moran, 28, of Adamstown, and Private R. Blackie, of Newcastle. Private Blackie's body was never found.

Ten others were taken to hospital, according to a Sydney Morning Herald report, published the day after the incident.

The report stated that the men were wearing "Mae West safety belts". [A nickname for inflated life preservers, due to them looking like actress Mae West's bust]

Mr Willcox was "in a brand new duck" that didn't sink. It rescued several men.

"I remember one duck was towing an LVT amphibious tank. The tank got swamped and dragged the duck down with it. We rescued the men from that," he said.

One survivor told the Herald after the event that he "saw a couple of sharks swimming round" while he was still aboard a vessel taking on water. The report also said some men couldn't swim or were poor swimmers.

Mr Willcox recalled members of Stockton Surf Life Saving Club being "pulled out of their beds" to help with the rescue.

The Herald reported that the lifesavers "pulled in five men who had been swirled around in the current about 200 yards from the beach for about three hours".

Mr Willcox said the lifesavers went to the surf club and "got a reel up the beach and pulled a lot of people out". They also brought blankets. The lifesavers were reported as Harry Rowlatt, Frank Littlewood, Bill Arthur, Barry Jones and Colin Whyte.

In the days after the incident, Mr Willcox recalled travelling along the beach from Stockton to Cemetery Point [now Birubi Point] "to see if we could find Private Blackie's body".

He also remembered travelling in an LVT to retrieve ammunition from a sunken A4 amphibious tank.

"It was just inside the break, down from Cemetery Point," he said.

Mr Willcox served in the National Service for two years under Australia's conscription laws. After three months of training at Holsworthy army barracks, he was "lucky enough" to be stationed at Camp Shortland, as he lived at Stockton.