"There are kids that have never been in the pool," he said.
The couple are delighted that the smallest boy in the class has managed to swim one length freestyle and one length backstroke after his lessons.
The Foleys ran a successful pharmacy for several years, which is how they have enough money to support the children indefinitely.
"We made our money from the community and we thought to give some of it back," said Mr Foley. "It helps to keep us young."
Tawhero principal Chris Dibben said he expected the Foleys to be sponsoring swimming lessons for the next 150 years.
Sport Wanganui and Sealord were also sponsoring the whole school to have lessons for an entire term this year, he said.
Mr Foley used to coach at Castlecliff Swim Club while Mr Dibben was learning to swim himself.
He approached the school to sponsor the lessons at the end of 2012, and said they "couldn't accept it fast enough".
The Foleys make it to every lesson to watch the kids learn, and say it's satisfying seeing their progress.
Mr Dibben said they were "part of the family" now.
"These guys get a cuddle from all the kids as they come in."
They had also bought togs for the children, and swimwear company Zoggs sent through 20 pairs of togs as well.
Volunteers drive the children by bus to and from the Splash Centre, while the Foleys pay transport costs.
Rob Cruckshank - who has two nephews in the class - and his father Shaun help drive the bus.
Children started lessons at the age of 6-7. "They love it," said Mr Dibben. "They're blown away."