Richard Cousins, 58, his sons, Ed, 23, and William, 25, Emma Bowden, and her daughter Heather, 11, were visiting Australia on the trip-of-a-lifetime when they embarked on the popular “fly-dine” sightseeing trip with their experienced pilot Gareth Morgan, 44.
Close friends Kurt Bratby, Todd Sellars and Lachlan Hewitt said they were spending New Year’s Eve on a houseboat on the Hawkesbury River when they saw the light aircraft nosedive into the water nearby.
They sped towards the site in a smaller boat but in the seconds it took them to get to there, the plane was almost entirely submerged.
“I couldn't get the doors open because I kept running out of air,” Mr Sellars told The Daily Telegraph.
“It was awful because we knew people were in there and we couldn't get them out.
“The only way I could tell where I was going was to feel my way down the sides of the windows... it was pretty dark down there.”
Will McGovern, who watched his friends’ extraordinary attempts, told the ABC that they showed incredible bravery in the face of debris and heavy fumes from the fuel.
"The families of these poor people they need to know people were there risking their lives trying to help their family members," he said.
"There was someone there trying to do something."