The two-time world champion and Olympic medallist said that being properly prepared for the water during the hot summer months is crucial.

"We want everyone to enjoy our beautiful waterways this summer but it's vital, whether you are an Olympic level swimmer or not, that you know your limitations," Mr Magnussen said.

There were 46 drowning deaths in New South Wales during last summer. Rivers accounted for more fatalities than beach-related incidents.

"Blokes tend to take the most risks, the statistics show that, so keep an eye out for your family and friends and please learn to swim, it's a skill for life," he added.

Sadly 98 people lost their lives on the water between July 2018 and June this year, RLSNSW CEO Michael Ilinsky said.

"It doesn't matter where you swim, you can get in trouble in a swimming pool just as much as a dam, creek or river. We encourage everyone to enjoy our waterways but let's do it safely by making sure of a few simple things," Mr Ilinsky said.

Learn to swim - it's a skill for life

Avoid drugs and alcohol

Always wear a lifejacket

Know your limitations; and

Keep watch for your family and friends

"Of great concern to us is the significant number of people who get into trouble and are classified as poor or non-swimmers, you have to know your limitations," Mr Ilinsky added. Anyone on the water should be prepared.