The figures come just over a week after teacher Leslie Gelberger, a father of two young children, set off for an ocean swim from Narrow Neck Beach on Auckland's North Shore and never returned.
The next day his body was found along the coast at Mairangi Bay with a leg missing.
Police are investigating whether Gelberger was struck by a Ports of Auckland pilot boat. The port has confirmed it will conduct an internal investigation once the police probe is complete.
New Zealand has one of the worst drowning tolls in the developed world, with an average of 77 drowning deaths per year.
Jonty Mills, chef executive of Water Safety NZ, said hospitalisations as a result of recreational activities on our beaches, lakes and rivers are on the rise and called for more education.
Mills said the demographics of people using waterways and beaches in New Zealand is changing - bringing a new set of safety problems.
"In Auckland in particular an increasing number of older people are taking part in water-based activities, which is creating a few issues," he told the Herald on Sunday.
"And there are increasing numbers of people from overseas coming here to live, many of them from countries which don't have an aquatic background."
Mills said the focus is now on education for children. Significant investment will be ploughed into educating kids from 5-13 about safety on the water, he said.
"If we don't do this, more and more people won't have these basic skills and in the long term it can only mean a spike in the number of drownings and accidents in the future."
Gelberger will be farewelled today when family and friends gather at Westlake Girls High School - where he taught - for a celebration of life event.
More than $12,000 was raised in an online fundraiser to help cover the event's costs.
A further $42,000 has been raised in a separate online fundraiser to support Gelberger's family after the tragic death.
In a post to those who have supported the family, Gelberger's widow Laura McLeod wrote last week: "Thank you to each and every person who contributed and thank you to the many others who have offered support in so many other ways.
"This horrific, awful, terrible, life-shattering event has been made more bearable due to the unending support from so many people.
"There are no words to adequately express my gratitude, that so many care enough to reach out has been humbling."