All three men were in the water line close to the shore, he said.
"One was described as very weak, no energy and not very well."
Beech said the Maketu Coastguard used their rescue jet ski and Kohinui rescue boat to help bring the men safely to shore.
One of the men needed urgent medical assistance and was flown to Tauranga Hospital in the rescue helicopter, he said.
Beech said witnesses reported seeing the boat enter the bar crossing from the wrong angle, before missing the channel.
"A wave came up behind them and flipped them," he said.
Beech said all men on board the boat were wearing their lifejackets.
He believed the men were taking a maiden trip and had misjudged the bar crossing.
Beech encouraged people to attend the coastguard's regular bar crossing training courses to learn how to make the crossing safely.
About six volunteers from the Maketu Coastguard attended the hour-long rescue, alongside firefighters from the Te Puke and Maketū fire brigades and St John Ambulance.
The man had since been discharged from hospital and coastguard volunteers had returned to salvage the boat, Beech said.