Jack Smith is a surf lifesaver, but on a day off at the beach with his girlfriend he never expected that's what he would end up doing.
The couple had just arrived at Piha when Jack, 18, spotted a distraught young woman near the water.
"We'd just sat down and we saw a girl crying and screaming. She was quite hysterical," he said. "I ran up to the girl and asked her what had happened and she said her sister and friend were in the sea with her and she didn't know what had happened to them."
Jack didn't waste any time.
"I ran down to the water but I couldn't see anything. I ran into the water but immediately felt the rip so I came back out and ran about 150m north.
"I saw a girl walking into the beach, the water was about waist deep. I ran up to her and she told me she thought her friend was dead. She was clearly in shock, she thought her friend had drowned."
Another man had joined Jack in the water and helped the girl to shore as he started to swim.
"I found the girl unconscious, face down in the water," Jack said. "I lifted her up and started to bring her back into the beach. Another guy came and helped me and when we got her on to the beach we started to do CPR."
Jack performed CPR for at least 10 minutes before the police Eagle helicopter arrived and officers started to help.
Soon after the Auckland Westpac Rescue Helicopter landed and paramedics took over and managed to resuscitate the teenager. She was then flown to Auckland City Hospital in a serious condition.
Police said later that day that the young woman was 19 and at the time she, her sister and friend went into the surf conditions were poor and there was a king low tide and large rolling waves.
A strong rip swept the trio about 200m out to sea.
Jack has been in contact with the teenager's sister and believed she was doing okay.
"I was so worried," he said.
"Her sister told me that she was in an induced coma for a week. They thought she would either not wake up or wake up with brain damage. But after a week she woke up with no signs of damage."
Jack is a volunteer at the Red Beach Surf Life Saving Club and said his training kicked in when he knew someone was in trouble. It was a natural reaction to risk his own life by entering the surf.
"I had to do something," he said.
When asked if he considered himself a hero, Jack laughed.
"No, I wouldn't say that ... I'd definitely do it again, for sure."