More than $35,000 has been raised through Givealittle for the family of Leslie Gelberger, who died while swimming last week.
Mr Gelberger was described as "a much loved husband, father and friend" by his wife, Laura McLeod.
The couple had moved to New Zealand from Canada three years ago, along with their two young children.
Mr Gelberger was a teacher at Westlake Girls' High School and was the only source of income for his family at the time of his death.
More than 500 people have since donated to the page set up to support the family, with the creator saying Ms McLeod needs their support "more than ever at this time".
Ms McLeod said she was left shattered by the loss of Mr Gelberger.
"I have lost my best friend, the best father to my boys and the most amazing, kindest, positive and adventurous person I have ever known. I didn't believe that Hollywood romance was real until I met him," she wrote in an email to Newshub.
"He was the yin to my yang, and I really don't know how we are going to cope without him.
"We are shattered, but supported by some of the most amazing friends we have made here."