A nearby surfer and bodyboarder helped Alex get the two boys on to the boards, with one of the teens having taken on a lot of water.
"He was pretty pale and couldn't really talk or do anything for himself.
"Getting back in was really, really hard, dragging him along, the current was so strong."
The boy was put on oxygen by ambulance staff and taken to Tauranga Hospital.
Eastern Region Surf Lifesaving education manager and Alex's dad Leigh Sefton said: "I have no doubt we would've had a tragedy if she hadn't been there".
Mr Sefton said the quick-thinking and actions of the lifeguards along the beach saved a number of lives from close calls with drowning.
A deep "gutter" in the land before the sand bar combined with the wind and tides created the dangerous conditions for swimmers, he said
"It is very treacherous in the wrong conditions."
Most of the people rescued were swimmers or bodyboarders without flippers, outside the flagged area on Main Beach..
A local man had swam out to help a 63-year-old woman struggling in the water on Christmas Eve and both needed rescuing by surf lifeguards.
Mr Sefton encouraged people to call 111 if they did not have the skill set to swim out and help.
"When you reach someone out there they just want to grab on to the biggest object out there which is the rescuer.
"If you do have the skill set to swim out there then it's best to take a flotation device with you like a surfboard or something," he said. NZME.