"We're asking people to draw a line in the sand, stop and think before they enter the water," Paul Shannon of Life Saving Victoria told reporters on Wednesday.
A 34-year-old man drowned at Sydney's Clovelly Beach on New Year's Day, and man in his 40s also died after being pulled from a popular swimming spot on North Stradbroke Island in Queensland.
Max Tavai, 45, drowned on Tuesday at Paynesville in Victoria.
"He was an awesome son, big brother, uncle, manny and friend. He will be missed," Aquila Momo Tavai posted online in a statement on behalf of the family on Wednesday.
Mr Tavai is the sixth person to drown in the state since Christmas Eve and the ninth since December 1, making the drowning death toll four higher than the five-year average.
"People need to be aware of their circumstances and don't overestimate their abilities when it comes to getting into the water," acting Victorian premier Tim Pallas told reporters on Wednesday.
He said the government had increased access for children to take part in swimming lessons and recently rolled out geo-located advice in a variety of languages so people were better alerted to dangers.
"(But) when you are confronted with situations where we've had six deaths over the Christmas-New Year period, I think it does demand that we continue to look at what more we can do."
Temperatures are set to soar above 40C on Friday in parts of Victoria and anyone planning to cool off at the beach is urged to swim in supervised areas and be aware of their ability.
Life Saving Victoria advises anyone caught in a rip current to stay calm, conserve energy and try to raise the alarm.
"Your vocal cords is probably your best armoury," Mr Shannon said.
"To yell and call for help, presuming you're not by yourself, is probably going to be your best mechanism early before you really get into any trouble."
A 66-year-old man was also pulled from the water in northern Tasmania on New Year's Day and could not be revived, but police say the death appears medically related.
In another incident, a 54-year-old man died on Wednesday after falling from a jet ski at South Stradbroke Island.
Police say it is not yet known why he fell into the water.