The money raised will go towards vaccinating children in third-world countries against the polio virus.
One of the organisers, David Jones, said they noticed last year how enthusiastic the children were to swim lap after lap.
He said all participants received a certificate which stated how many laps they swam and how many children's lives they saved.
"Every child vaccinated is a safe child," Jones said.
Another organiser, Tak Tothill, said it would be a "bang for your charity buck" with every dollar donated tripled by the Bill and Melinda Gates Foundation.
The Rotorua club's goal is to raise $5000, which would mean 5000 children in a third world country would be vaccinated against polio.
While kids swimming for kids is the theme, anyone is welcomed to take part in the swim, as well as come along to support.
The money is not being used for New Zealand polio vaccines because they are funded by the Ministry of Health.
Tothill highlighted the importance of the movement as polio was preventable through immunisation.
Poliomyelitis (polio) is a contagious, incurable viral disease which can cause disability and disfigurement, as well as death.
While New Zealand had been polio-free, with no cases of wild polio infection since 1970, the late effects of polio continue to affect thousands of New Zealanders.
"This generation is lucky to never have seen it first-hand," Tothill said.
Last year, there were 10 confirmed cases of polio in Papua New Guinea and Tothill said that was "too close to home".
Rotary is a global organisation that aims to take action against global issues.
As a founding partner of the Global Polio Eradication Initiative, Rotary stated on its website the organisation had helped reduce polio cases by more than 99.9 per cent and was aiming to completely rid it from the last three countries where it was still endemic to keep other countries polio-free.
"If all eradication efforts stopped today, within 10 years, polio could paralyse as many as 200,000 children each year," Rotary's website said.
Donations can also be made to Rotary Rotorua Sunrise through its bank account
020 416 0039777 00
The details
What: Rotorua Swim Marathon charity challenge
When: Tomorrow, 9am to 12pm
Where: Rotorua Aquatic Centre
