The Francie's skipper, 68-year-old Bill McNatty, was among those who had died, said people close to him within the Kaipara boating community.
Steve McGregor, commodore of the Kaipara Cruising and Sports Fishing Club, said McNatty's death had been confirmed to him by his girlfriend Wendy Marshall.
Club members have been arriving at the club this morning to pay their respects and remember McNatty, who was the club commodore in 2008 and a current committee member.
Several bunches of flowers have been left at the base of the club flagpole where the New Zealand flag is flying at half mast.
McGregor said McNatty was a valued member of the club.
"It is quite devastating for all of us. It's a sad day.
"He was a happy go lucky sort of chap. He lived to do things on his boat. He did lots of maintenance on the boat and had just finished putting in a new diesel tank.
"He is a great asset to the club and is going to be missed," McGregor said.
Bill 'Butcher' Reid, an old friend who had driven up from Hamilton to pay his respects, said McNatty had found his niche in Helensville with his boat.
He was a very fussy person, very particular and a good seaman, Reid said.
"Bill had a brilliant personality and a happy dry sense of humour. He was a happy man and kept to himself," said Reid.
He said he first met McNatty through Hash House Harriers in Auckland in 1983 where he earned the nickname Cat Weasley.
Susan Strassnick, who was McNatty's landlord in Helensville for 18 months, described the skipper as an environmentalist and "a very lateral thinking man".
"He is into alternative things and takes a very holistic approach to the world."
She said McNatty, who had lived in Helensville for about 13 years, worked on a sand barge before becoming the Francie's skipper.
"He was ready to laugh and had a great sense of humour," Strassnick said.
She said McNatty had been planning to move to Shelly Beach, where his charter business operates.
McNatty's daughter, 23-year-old Kathleen-Jane Hotere. had recently qualified as a day skipper herself, Fairfax reported.