More than a third of boaties who died by drowning last year either did not have a life jacket on or did not put it on properly - rendering it useless.
Water Safety New Zealand has today released its 2019 Provisional Drowning Report; showing a marked increase in the number of people who drowned last year compared to 2018.
The provisional results show 78 preventable drownings happened last year - 12 more people died in New Zealand waters than the year before - when the death toll stood at 66 deaths.
Of significance was the dramatic increase in the number of people who died in land-based fishing incidents - where there were 12 deaths compared to six the year before - and during underwater diving activities when 11 people died compared to the five people who perished in 2018.
There was also a spike in those who died while out on a powered boat. Last year, 11 people were killed on the water - a huge jump from the two deaths recorded in 2018.
• Napier boy's drowning: Outpouring of grief for Marama Te Pou, 7
• Six people drowned over the holidays - two more than last year
• Drowning tragedy: Boy dies at Karioitahi Beach, two others survive
• School-trip beach tragedy: Melville High School student Jaden Chhayrann missing presumed drowned
Chief executive Jonty Mills said: "Every one of these preventable deaths is devastating for a family and a community and has real and profound impact on many people's lives.
"While our waterways are our playground, they can be incredibly unforgiving and need to be treated with respect."
Mills said the toll reflected the complex nature of drownings in New Zealand.
"Drowning is not one-dimensional. The numbers represent a wide range of ages, ethnicities, activities and water environments."
The heartbreaking figures also include the deaths of seven children aged under 5 years old. In 2018, that number was three deaths.
"Be prepared, watch out for yourself and each other, be aware of the dangers and know your limits."
The report comes as there has been a spate of drownings around the country in the last few weeks and months already.
Water Safety NZ's latest figures, officially, show that there have been 20 deaths by drowning around New Zealand as of Friday, February 21. There were 22 drownings the same time last year.
It is understood the latest figures - due to be updated on Friday - do not include the latest water incidents.
That includes 14-year-old Chase Swanson-Ewing, who went missing after an incident on the Whanganui River on Thursday night. His body was recovered about 1pm the next day.
Chase's mother, Louisa Baldwin, is now calling for mandatory swimming lessons from primary school age.
Meanwhile, a search for missing 17-year-old Jaden Chhayrann, of Hamilton, is now in its fourth day after he was swept out while on a school trip at Waihī Beach on Friday.