The number of deaths from drowning in 2008 was the second lowest since records began in 1980.
Water Safety New Zealand general manager Matt Claridge said about 80% of the 96 people who died were men.
He said the number of drownings has fallen over the years because children were taught to swim at school from the 1960s.
However Mr Claridge said many children now have limited swimming tuition or none at all, and Water Safety New Zealand predicts the number of drownings will rise to 180 a year by 2030 if that does not change.
Mike Byrne from Swimming New Zealand said there needs to be a significant change in attitude from the Government, which must make swimming programmes in school a priority.
Hurunui River drowning
Meanwhile, police have released the name of a father of two who drowned in the Hurunui River in North Canterbury on Wednesday.
John Watson Marr, 47, known as "Wattie", of Greta Valley, died while swimming in the river near State Highway 1, just before 5pm on Wednesday.
Inspector John Doherty said on Wednesday that family members lost sight of the man and called police.
A rescue helicopter was sent and four jet boats searched the river in the Greta Valley area.