Lincoln Davies from the Auckland Westpac Rescue Helicopter said a man in his 50s was taken to the hospital.
CPR was performed by the lifeguards and the man was revived.
Two other people were treated with minor injuries and were left at Karekare Beach.
A Surf Life Saving New Zealand spokesperson said the incident occurred after the flags had been put away. Local lifeguards were alerted to two swimmers in difficulty and responded in an IRB.
Northern Region Lifesaving operations manager James Lea said the weekend saw higher incident numbers than you'd see in peak summer.
"In total our lifeguards did 52 rescues, assisted six people to safety, performed four major first-aids and searched for eight people – that's really unusual for a weekend in November," he said.
"It was a combination of thousands of people being at the beach because of the hot weather, along with decent swells, warm water temperatures and outgoing tides for most of the day."
Lea said most of those who got into trouble over the weekend were caught out by flash rips.