Three people had to be rescued by the Coastguard this afternoon after their boat capsized in Manukau Harbour as they tried to cross the treacherous Manukau bar.

Around 4.30pm a member of the public called the Coastguard, saying they had seen a man clinging to the side of an overturned boat, operations manager Ray Burge said.

The Coastguard dispatched their Air Patrol plane and the NZ Steel rescue boat to the scene just after 4.30pm.

The man told Coastguard two other people were missing and all three had been in the water for several hours.


They were located by Air Patrol who directed the rescue boat to retrieve them.

"They were found alive fortunately," Mr Burge said.

"They had lifejackets on and were hanging onto a chilly bin."

The two people in the water were hypothermic and the third man had chest pains and sore arms and legs.

All three were taken to shore by boat to a waiting ambulance.

Mr Burge could not confirm whether they had been taken to hospital but said it was likely they had.

St John's were not immediately able to be reached for comment.

The Coastguard could have found all three people much quicker if they had sent through a bar crossing report, Mr Burge said.

The Manukau bar is a rough stretch of water which many boats get into trouble in while crossing.

"These people had not lodged a bar crossing report with Coastguard.

"If they had we would have known they had an incident much sooner and we would have reached them much quicker." A bar crossing report is when boats let Coastguard know they are about to come through the bar, and check in again once they have successfully crossed.

Mr Burge said boaties should lodge a report every time they crossed the bar.

"Get that message out there. It could save a life, it absolutely could."