"I do this because I love it. It keeps me young. It keeps your mind ticking."
It also means a lot of people greet him when he's out and about around town.
There's not enough learn-to-swim teaching available, he said, and many schools don't have pools.
"People can go to the Splash Centre, but the costs are just too great for them."
He's not a "bully coach" like some people, and prefers to encourage children. Last year a group of Catholic children asked him to go to Mass with them. He's not Catholic, but he went.
"They fell all over me at church, they were so rapt," he said.
One grateful parent this summer is Antonia Gregory. She has nine children and Sollitt taught her eldest to swim when he worked at Whanganui East Pool.
Over the past three weeks she's watched a child who was a borderline swimmer make fantastic progress.
"The little ones have gone from being scared of the water to floating and putting their faces in."
One boy, 13-year-old Francis Gregory, told Sollitt he wants to be coached for competitive swimming.
It's sometimes cold taking the lessons, but it's worth it, he said.
"It's good doing hard work and feeling it after."
When this summer's classes are finished Sollitt will coach even more children - but after school.
"There's always a call for it. It seems to get worse when school restarts," he said.
Sollitt became a competitive swimmer himself, in 1952. In the late 1960s he started coaching, at Pukekohe.
When he returned to Whanganui in 1979 he went back to his old club in Whanganui East. Until about five years ago he managed and taught at the Whanganui East Pool.