Off-duty lifeguards have rescued a group caught in a rip in Port Waikato

Three children and an adult got in serious difficulty after entering the turbulent surf.

They were spotted by six off-duty lifeguards from the Sunset Beach Surf Lifesaving Club.

One patient is being taken to hospital by Westpac Rescue Helicopter - the three others are in a stable but shaken condition.

Surf Life Saving New Zealand say if they hadn't been spotted, it's likely they would've drowned.