If it weren't for Rocco Conaghan completing CPR training in the last six months, a young girl rescued from drowning in a pool wouldn't be here.
The girl was brought back to life after she was found face-down and blue by Conaghan's friend in the Miranda Holiday Park's hot mineral pool in Thames on Monday night.
Conaghan's father Dave says that without the teenager's quick actions, there is no doubt in his mind the girl would have died.
"We're very proud but it was an extremely stressful situation," he told the Herald.
The near-drowning took place around 8pm on Monday, with police, St John ambulance, and the Auckland Westpac Rescue Helicopter all called to the scene.
Before they arrived, 15-year-old Rocco worked desperately to bring the girl back to life after she was plucked out of the water by a man.
"I wasn't sure if I was supposed to do anything because I wasn't sure if anyone else knew what to do - they didn't - I saw what they were doing and knew it was wrong," he said.
"I ran through the steps I learned at my first aid course and started CPR because she wasn't breathing or responsive."
Rocco worked alongside two women who gave the girl two breaths, 30 compressions twice and another two breaths and 16 compressions before she regained consciousness.
He says the girl's mother was screaming with worry and Conaghan found the whole ordeal unnerving.
A dance teacher, the Takapuna Grammar Student was required to have completed a child first aid course with St John.
The course teaches the "DRSABCD" resuscitation method, which was still fresh in Conaghan's mind - but he never thought it would be something he would actually use.
"It was my first time ever using [my training]," Conaghan said.
"It was quite stressful."
It was clear the girl was in strife after they pulled her out of the pool because her skin had turned blue, Conaghan said.
By the time he started going through his CPR checks, someone had already called for an ambulance and he asked someone to grab a defibrillator.
The rescuers checked the girl's airways and got straight to work, getting the girl breathing again so they didn't need to use the defibrillator.
Conaghan was with six friends and relaxing at the holiday park pool when one of his friends discovered the girl face-down in the water.
"It puts a lot of value in first aid courses, to tell you the truth, really. It could have been a lot worse," he said.
CPR is a manual method of pumping blood around a person's body when their heart has stopped working.
It is not designed to restart the heart but keep blood pumping so heart and brain cells do not die due to a lack of oxygen, St John says.
All potential patients should be carefully assessed to decide what emergency response is necessary, and this is where the DRSABCD method comes into play.