A 42-year-old man who did not resurface after swimming in a dam on Christmas Day.

A 49-year-old man who disappeared near a waterfall while trying to rescue a child.

These are some of the stories behind the statistics from Royal Life Saving's summer drowning toll, with 54 people dying in waterways across Australia since December 1.

That figure is up from 48 drowning deaths in the same period last year.

The toll reveals men aged 18 to 34 are most at risk, while more people drown in inland waterways like rivers, lakes and dams than at the beach.

The Murray River, across NSW, Victoria and SA, is a drowning blackspot, along with the Yarra in Victoria, the Hawkesbury in NSW, the Murrumbidgee in NSW and ACT, the Swan in WA, and the Brisbane River in Queensland.

Royal Life Saving chief executive Justin Scarr said the calm surface of a river can be deceiving.

"People can neglect to understand the impacts of steep drop-offs or currents or snags moving through the watercourse," Mr Scarr told AAP.

"Rivers can change on a daily basis, and on an hourly basis.

"The rainfall we've had across Australia means many of those rivers have more water than they have had for many seasons."

Royal Life Saving's new campaign, Make the Right Call, urges men to wear life jackets while boating, never go out on the water alone, avoid alcohol and always check the weather conditions, even on inland waterways.

"One of the more significant factors in keeping men safe is calling for them to look after their mates," Mr Scarr said.

Royal Life Saving's national research manager, Stacey Pidgeon, said men have long been at highest risk of drowning.

"We tend to see males overestimate their abilities in the water, especially when alcohol is involved," Ms Pidgeon said.

"Swimming in a pool is a lot different to swimming in a river or at the beach.

"Rivers can have really fast-flowing currents, similar to rips and waves on a beach."

Regional and rural waterways present the greatest drowning risk because they are often isolated, so emergency help is further away and mobile reception may not be reliable, she said.

Mr Scarr said the campaign is vital because the effect of drownings can be far-reaching, particularly in country areas.

"In regional communities they have a close relationship with their rivers, so drowning deaths have a significant impact on communities, whether they know someone who has drowned, or they know people who have been involved in the search and recovery," he said.

"Drowning in regional communities has a snowballing impact."

Australian Associated Press