As Hayward pulled Joaquin from the water, Zac was dragged out to sea: "It was horrible ... I was just shouting to God to bring him back."
Tolley went to Zac's aid, and an exhausted Zac tried to climb on to his rescuer before Tolley put him in the diver's tow.
"He said to me later: 'I'm sorry, I had to manhandle your son'," Hayward said. "I was like: 'Seriously, you could have knocked him out and I wouldn't have cared'."
Tolley said he was not a hero, just someone who had a job to do. "This little boy is valuable."
The most important thing for someone in the same situation was to stay calm and assess the risks before going to help.
"I knew God had equipped me with the skills. I never feared for my life."
Hayward said she was disappointed an off-duty lifeguard did not swim out to Zac because she did not have a flotation device.
"She was awesome once they were out of the water, but she was adamant she was not going in."
Surf Life Saving Northern Region manager Tom Burgess said the lifeguard swam to the surf break and brought Zac back to shore and assessed him.
Lifeguards were trained to assess the situation and make sure they did not put their own safety at risk, Burgess said.
There were 93 drownings in New Zealand last year and three so far this year, as well as one man also missing in south Wairarapa.