Mrs Miller said they wanted as many people as possible signed up for the coming summer.
"It's a bit difficult to tell (how many we need) at the moment because a lot of them are at university and it depends who's coming back," she said.
"We want as many as possible because we want to offer the chance for them to go into surf comps."
Lifeguards begin their training next week and there was time for new recruits to be trained by December when patrols begin.
"For people who can swim 300m, we can get them up to 400m."
The current crop of lifeguards recommended joining the patrol.
"It's probably the best summer job you could have. It's a huge family," lifeguard Samantha Miller said.
Clarissa Nowak said: "you have a of responsibility but you learn a lot".
The open day will run from 10am to about 12pm on Sunday at the clubrooms at the bottom on Rangiora St at Castlecliff Beach.