When Altona’s Derek Wilson heard two people had drowned in Hobsons Bay on Saturday, he was heartbroken for the families.

Twenty years ago on Monday, Mr Wilson’s two youngest children – Molly, 4, and Ben, 7 – drowned along with two of their teenage cousins while holidaying at Gunnamatta on the Mornington Peninsula.

On Saturday, three men were in the water near Altona boat ramp at Seaholme when they began struggling about 4.30pm.

Jet-skiers pulled the men to shore and CPR was carried out on one of them.

A 19-year-old from Brooklyn died at the scene.

About 90 minutes later, a 41-year-old Footscray man got into trouble in water near the Timeball Tower at Williamstown. His friend managed to bring him to shore, where members of the community tried to resuscitate him, but he died at the scene.

Since Christmas, six people have died after being pulled from the water in Victoria.

Mr Wilson said his daughter, Molly, had been hit by a big wave and could not be revived while his son was resuscitated and placed on life support until he died.

“Ben had only spoken to me about six weeks earlier about being an organ donor – this was a seven year old,” he said.

“He said, ‘I’ll be an organ donor’, and I can remember saying to him, ‘You’re gonna be an old man, mate, and you’ll be all worn out’.”

Derek Wilson writes a tribute to his lost children in the sand at Gunnamatta on Monday.

Mr Wilson has since been instrumental in developing internationally-recognised beach signage of symbols to warn people of risks and arrows directing beachgoers to patrolled areas.

He said the signs were critical, together with water safety education in different languages.

“People are coming from overseas from countries that are landlocked, so they don’t have those sort of experiences,” he said.

“Or you get the family on holiday, not familiar the area … not knowing what the risks are.

“I feel for the families and friends of these two that have drowned. They will live with that for the rest of their lives.”

Seaholme resident Peter Weaver, who rescued two jet-skiers near Altona boat ramp on Saturday, agreed more education was needed.

He said the rescued pair had been wearing ineffective lifejackets.

“It was a hell northerly, so you’ve got to watch that you don’t get blown out into the middle of the bay,” he said.

“About 100 metres from the boat ramp, we saw a yellow jet-ski with nobody on it and we thought, that’s strange, so we motored across to them.

“Then we saw two people in the water. It was a father and son and they were screaming, ‘Help, Help.’

“We pulled them into the boat and the son said, ‘Thank God you came, another 10 minutes and he would’ve drowned because I couldn’t hold him up any more’.”