"The boat was returning from a day out on the water and came unstuck with all four passengers being thrown into the strong current and surf," Mr Baker said.
"Although they had a lot of local experience, the dangers and challenges of crossing the Mangawhai Bar were too much for them on this day."
Fortunately there were a number of surfers in the water, including local Colin Young, who managed to retrieve some of those in the water.
Off-duty Lifeguard Isaac Johnston also responded with a rescue board and local surfer Craig Freeman and retrieved the skipper of the boat.
Mr Baker said all four occupants were very stressed and the skipper was in a stable but stressed condition.
Once the 50-year-old skipper was brought ashore, former Mangawhai surf club president Greg Gibb and local business owner Dave Glover assessed the man in the club's first aid room.
"There were concerns he had taken on a lot of water and was struggling to breathe."
Lifeguard Jess Costello, who teaches First Aid, was called to help and make a full assessment of the patient before St John Ambulance arrived.
The man was taken to Whangarei Hospital by the Northland Rescue helicopter, and he was later discharged. A woman aged 50 and another also in her 50s were treated at the scene as was the girl.
Meanwhile, Mangawhai surf lifeguards after hours call out squad members Murray Dix and Mark Vercoe tried to retrieve the overturned boat using the club's Sea Rider.
Initial attempts were futile due to the strong current and low tide, but they managed to salvage and tow it back into the harbour later that evening.
Mr Baker said it was the second time a boat had flipped on the bar this year and there were a number of other very close calls over the weekend.
"The key area for concern was the fact that none of the passengers onboard were wearing lifejackets."
