The death toll from Victoria's horror day of drownings last week has climbed to four, with a young girl dying in hospital.
The four-year-old was found unresponsive at Lysterfield Lake in suburban Narre Warren on Wednesday.
She was taken to the Royal Children's Hospital in a critical condition and died on Saturday, police have confirmed.
They are not treating her death as suspicious.
Premier Daniel Andrews described Wednesday's spate of drownings on the Mornington Peninsula and in the Gippsland region and Melbourne's outer east as a "tragic day".
A woman in her 20s died after swimming out to rescue a teenage girl struggling in the water at Venus Bay, two hours southeast of Melbourne.
After setting off with several others, she got into difficulty and was pulled from the water by an off-duty lifeguard. Everyone else made it safely back including the teenager.
Earlier in the afternoon, four people were swept off rocks at Bushrangers Bay near Cape Schanck, close to the southernmost point of the Mornington Peninsula.
Two members of the public entered the water to assist, police said.
Aida Hamed, a Lalor-based Australia Post worker in her 40s, died and five other people were rescued.
Four of the group were taken to hospital.
The third death was that of a man in his 80s, brought to shore unconscious at the popular Rye Front Beach in Tootgarook.
