Brazilian-born Mr Abrao, 30, working as a lifeguard at the pools for three years, said the mother got to her son before he did and pulled him out of the water unconscious.
"I took the child from his mum and placed him in the recovery position and checked his airways. He started coughing up water and became conscious, but his breathing was very laboured."
Mr Abrao said he alerted other pool staff who brought him a life-pack kit and he administered oxygen to the boy, stabilised his condition, then took him to the first aid room.
"We continued to monitor his airways and he was still coughing up water, and we kept the oxygen on him until the ambulance arrived," he said.
"I didn't feel scared, I felt calm. We are trained to remain calm in a situation like this so we can be effective in emergency situations and follow the procedures correctly. I feel very happy the boy is alive ... As a father, it is easy for me to place myself in the place of the mother. I can imagine how hard it would be to watch your child suffer. I thank God the child is alive."
Mr Abrao said he felt proud of the role he and the other lifeguards played in saving the boy. "We are there to keep people safe and take the right action, that's our job," he said.
Bay Leisure & Events programmes manager Tina Harris-Ririnui said the organisation was "very proud" of the way Mr Abrao and other pools staff reacted.
Ms Harris-Ririnui said the pool manager had been in regular contact with the boy's mother and was told he was recovering well.
He was in a stable condition last night.
"The mum had been very attentive of her children but turned her back on her son momentarily to attend to her other child on the other side of the toddler's pool, less than 10 metres away. This incident emphasises how important it is to keep children within arm's length."
Bay Leisure and Events chief executive Gary Dawson said: "Claudio has done an amazing job. He did everything we would have expected of our lifeguards."
Mr Dawson said he hoped the boy would be okay and his thoughts went out to the boy's family.
Keeping children safe in water
*Ages 0-2 years: Always maintain hand contact with babies and stay within sight and reach of your child
*Ages 1-5 years: Stay within sight and reach of your child when in, on and around water
- Safekids Aotearoa