Mrs Cook has been paying for her two children to have swimming lessons at the pool once a week since 2007 but was planning to enrol them elsewhere next term.
"We believe that reinforcing, later in the week, what our children learn on a Monday can only be a good thing and find it staggering that the pools will not allow this."
Mrs Cook has taken her children to swim laps at the pool and offered her own advice to them on other occasions and found the staff happy to help, but on the two occasions during the last two weeks when Ms Purton supervised the three boys, she was hauled into the office and shown the contract.
"I wouldn't have thought there would be any type of restrictions on what you can do in a public facility when you are paying to use it. When other people have tried to do this [the same thing] they have been charged lane hireage of $50 an hour," she said. "I think the Greenpark School challenge is an awesome challenge. How are the kids meant to be able to do that if they are not allowed [to practise]? I'd hate for people not to be able to learn to swim."
With 98 drownings in 2012 children need to be encouraged to learn to swim well, Mrs Cook said.
A spokesperson for Greerton Aquatic and Leisure Centre told the Bay of Plenty Times a formal response to Mrs Cook's complaint was being prepared but she was not at liberty to comment.