As the summer drowning toll climbed to 18 on Tuesday, YMCA chief executive Leisa Hart has suggested that the government offer rebates on learn to swim classes, which cost up to $300 for a 10-week term.

This could be followed up with compulsory swimming lessons in primary school, she said.

Those who have drowned in NSW since December 18 include four toddlers and two school-aged children, while another two-year-old boy remains in intensive care.

Royal Life Saving NSW has reported that half the state's primary schoolchildren are unable to swim by the time they enter high school.

In an opinion piece for Fairfax Media, Ms Hart said the federal government had a role to play in ensuring that every child was given water survival skills.

The fees for swimming lessons needed to cover the wages of the instructors as well as hidden costs such as the annual renewal of their qualifications, pool hire, pool maintenance and child protection courses, she said.

"Definitely the cost has risen," Ms Hart said.

"I know that this cost makes lessons impossible for some parents.

"How do we work with places like the Royal Life Saving and Austswim to teach kids and how do we work with the government to make it more accessible? I think the perfect leverage is working through all the schools."

The Victorian Government announced in November it would make swimming classes a compulsory part of the physical education curriculum, but did not commit any funding to the scheme.

A spokeswoman for Education Minister Adrian Piccoli said the NSW Government already pays for swimming instruction of public primary students in years two to six, but parents are expected to pay for the pool entry and transport.

About 100,000, or about one in four, students participate annually in the optional program, which covers water safety, water confidence and survival skills. Theoretical water safety is also a compulsory part of the school sport curriculum.

Emergency Services Minister David Elliott pleaded on Tuesday for people to take responsibility for their safety, saying he was horrified that some people lived in NSW and did not know how to swim.

"Government can't be at every creek. Government can't be on every river bank. Government can't be at every beach. Government can't be in every backyard pool. That's why we've got to work collaboratively with the community," he said.

The YMCA charges $222 for a 12-week learn to swim program at UNSW or $32 per fortnight at the Mariners Centre of Excellence on the Central Coast.

Meanwhile, the cost of Austswim-accredited courses ranges from $130 for a 10-week term for the Aqua learn to swim classes that run at council pools in Blacktown, to $165 at Birrong Leisure Centre and $185 at the Ashfield Swim School.

But some private providers charge considerably more.

Little Heroes Swimming Academy charges $250 for a 10-week term at its Domain, Putney and Bondi locations and $300 at Kincoppal Rose Bay.

The academy is a registered charity that uses the income raised from its mainstream students to support the lessons it provides for special needs children.

Royal Life Saving NSW operations manager Michael Ilinksky said although learn to swim classes increased water confidence among toddlers, there was no evidence they would save their lives until they were about four.

This was because such classes taught children how to float to the surface and reach the edge, but the conditions under which they would fall in a pool – fully clothed, into cold water, without their parent nearby – were vastly different from the practice.

"These lessons are very repetitive and the costs of these lessons become significant," Mr Ilinksky said.

"We just need to be careful about what we encourage parents to do."

But he said every school should have a compulsory water safety program that included a practical element, and swimming should not be forced to compete against cheap and popular sports such as football and netball.

"We're encouraging every secondary school in particular to pick up life saving because of the options it gives you in life.

"If you're a safe swimmer, surfing is an option, scuba diving, white water rafting and a whole range of experiences are open to you. It's different to kicking a football or shooting hoops."

Paramedics said they had responded to 225 drownings or near drownings in the past two months.

NSW Ambulance Inspector John Brotherhood said these included a two-year-old who fell into a front yard fountain and a toddler who fell into a nappy bucket.

"Another case we attended, the lock was broken on the pool gate and the family thought, 'We'll get around to it'," Inspector Brotherhood said.

"In almost every case I've attended, it's been the same story, the pool gates haven't been fixed; the parents have been distracted or the kids have wandered out and got into trouble."

Update: Further information has been added about the Little Heroes Swimming Academy charging structure.