The new research also shows more than half of all adults drink alcohol around the water, even though alcohol is one of the biggest risk factors for adult drowning.
"Alcohol impairs your judgement and changes your risk perception and ability to respond if you get into trouble," Royal Life Saving chief executive Justin Scarr told AAP.
Mr Scarr said a lack of familiarity with swimming, boating and fishing spots also increased the risk, because visitors may not be aware of sandbars, currents, rips, obstacles and fast-changing conditions.
"Add to that the fact a lot of us have been out of the water during the pandemic and are out-of-practice and you have a perfect storm," he said.
He urged people to avoid drinking alcohol around the water, avoid going alone and encouraged wearing a life jacket when swimming, fishing or boating.
Between July 1, 2020 and June 30 this year, 294 people died by drowning, a 20 per cent increase on the previous year.
RLS estimates another 674 experienced a near drowning incident, with rivers the most dangerous locations for drownings.
Already this summer seven Australians have drowned.
The research analysed cases in the Royal Life Saving fatal drowning database which dates back almost 20 years, along with conducting a survey of how Australians behave around the water.
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