"This incident could easily have resulted in multiple fatalities, but for the fact that the life jackets on the boat floated to the surface near the boat following the capsize, and the occupants were then able to grab them."
The group of four were able to make their way to Matakana Island, where they were rescued by a passing boat.
Once the alarm was raised, a search immediately started for Mr Mair but he was not seen until his body was found floating in the sea off Whiritoa Beach on February 7.
Coroner Ryan said he was satisfied from the evidence provided that an extensive search was undertaken for Mr Mair, but he could not be found because it is likely he was submerged at the time.
"There is no evidence to suggest that the search was deficient in any way, and by this time Mr Mair's death could not have been avoided."
Coroner Ryan said it was a legal requirement for every pleasure boat to have a personal flotation device (PFD) on board for each person while in Tauranga Harbour.
The Bay of Plenty Regional Council's guide for safe use of the harbour stated it was a legal requirement for everyone to wear a PFD in all situations where there was a heightened risk.
Coroner Ryan said if Mr Mair was not aware of this requirement, he should have been, as he was the skipper of a boat using the harbour.
"This responsibility was even greater, given that he was carrying passengers.
"If Mr Mair was aware of this requirement, then for reasons known only to himself, he chose to ignore the rules.
"Whichever of these applies, Mr Mair has paid the greatest penalty for failing to observe best practice, if not legal requirements, for the safe operation of a pleasure boat."
At the time his body was found, Mr Mair's father Selwyn Mair told the Bay of Plenty Times it was "A terrible loss and he will be missed by his family, children and grandchildren.
"He was a much-loved family man and he will be hugely missed."