"The pilot launch stopped its engines, listened and then heard him crying for help," the Port of Tauranga's duty watchperson told the Bay of Plenty Times.
The watchperson, who asked not to be named, said the cries for help were first heard at 3.40am on Saturday and the fisherman was picked up by the Arataki 15 minutes later.
He was rescued about 200 metres northwest of the port's B-buoy, which is anchored by the shipping lane off Mauao's North Rock. His 14ft (4.3-metre) tinnie was tied to the buoy and taken back to the port on Saturday morning, where it was picked up by the man's father.
There were confused reports about how long the man was in the water after his boat capsized. He initially told his rescuers it was three hours but later told police it had been six hours.
"God, I would not want to be out in that weather, even a 20 knot wind would be too much for a boat like that. You would just not do it - he was very unwise," the watchperson said.
Sergeant Carl Purcell of Tauranga police said they could only go on what they were told, although he could not imagine how the man would have clung to the dingy for six hours in those weather conditions.
Mr Purcell said it was clear that the man was intoxicated. Police were told he had been out fishing on Friday afternoon and had returned to shore to have a few beers.
"He then went out again with a few more beers."
Mr Purcell said the man's actions were "absolutely ludicrous". He not only put his own life in danger but forced others to put themselves at risk by saving him.
"It was incredibly stupid ... he is lucky to be alive."
The police, who interviewed the fisherman at Tauranga Hospital, said they were treating the incident as a foolish act.
Another port official described the man as "short and skinny, with no meat on his bones". He also doubted the man had been in the water for six hours because conditions had been "pretty terrible".
He was not wearing a life jacket, even though life jackets were in the dingy's locker.
Even cruise ships Diamond Princess and Sun Princess delayed their departures until about 4am on Saturday because of the strength of the winds howling down the harbour. The winds eased off after midnight to about 20 to 25 knots, gusting to over 30 knots.
An ambulance waited at the port to take the man to hospital. He was suffering from hypothermia, although he was able to walk and talk and did not seem to have suffered too badly from the experience.