More than a third of the claims made last year were for children under the age of 10 - of those, 111 were under 5 and 39 were between 5 and 9. In 2015, there were 84 claims for children under 5.
The figures look particularly grim when paired with a spike in the number of preschoolers who have died in preventable water accidents.
Seven children under the age of 5 have died in preventable water accidents so far this year compared to two at the same time last year.
Whanganui local Mason Toohill, 5, is one of those who could have died when he drowned in an incident his mother Holly called "terrifying".
The boy, who was 4 at the time, was playing in the pool at the Whanganui Splash Centre in May this year when his mum noticed something was wrong.
Mason was bouncing around in the water and kept going under, then coming up again, she said.
"I was like, wow, he's been holding his breath for way too long. So I called out to him and he jumped up. And then he went down again and my heart started beating - I knew something was wrong.
"He was bobbing... it was the weirdest thing, so surreal. In the end I reached in from the side of the pool and pulled his shoulder, and he kind of floated on to his back. He was all blue and he looked terrified."
Toohill said she had recognised the signs of silent drowning after having read about it online.
"I pulled him out of the pool with one arm and ran to the lifeguard and I lay him on his back. He wouldn't talk, he wouldn't do anything. I was freaking out."
From there, Toohill said everything was a bit of a blur. Mason seemed to start breathing again pretty quickly and he spewed out some water but was otherwise unresponsive.
At the hospital, doctors told Toohill that once water got into the lungs, the body becomes instantly exhausted. It could take just a matter of seconds for things to go very wrong.
Seven months on, Toohill said she still has nightmares about the incident.
Her attitude around water safety had changed drastically - Mason's paddling pool is gone and at social events like barbecues she now faces the pool so she can keep an eye on the kids.
Toohill said she was relieved Mason hadn't suffered any long-term medical impact from the incident.
"It definitely went through my head when we were waiting for that ambulance, and he was awake but wouldn't talk, he wouldn't move... It went through my head that he could be brain damaged."
Starship children's hospital director of child health Dr Mike Shepherd said for every one child that died as a result of drowning, approximately five more sustained some degree of permanent brain damage as a result of drowning.
"The types of injury that we see that are the most serious relate to hypoxic brain injury - essentially children not getting enough oxygen to their brain for a period of time," he said.
Shepherd said on the severe end of the injury spectrum a child could sustain a brain injury making them incapable of carrying out normal activities or caring for themselves.
Families he worked with at Starship following this kind of event were typically shocked at how fast it happened and how long-lasting the impact would be.
"So the real tragedy in this is that lifelong consequence of a brief moment of inattention."
According to Water Safe, our drowning toll would be "catastrophic" if it wasn't for the efforts of the wider water safety sector.
Surf lifesavers were kept busy on Christmas Day, with Surf Life Saving staff carrying out about 17 rescues. These included swimmers trapped in rips, falls on rocks and burnt feet.
On Monday evening a man was rushed to hospital in a critical condition after getting into trouble in the water at a boat ramp in East Auckland.
Chief executive Jonty Mills said with the under-5s age group any amount of water was a hazard.
Tips for keeping your young ones safe this summer
- Fence your pool properly. Shepherd says a fully fenced pool is essential, as constant supervision isn't possible.
- Be aware of other water hazards. In rural properties, they might be water hazards you haven't considered, like water tanks and ponds.
- Keep smaller water hazards out of reach. Things like nappy buckets can be a death trap for small children if left lying around.
Source: Mike Shepherd, Starship Hospital
Costs for active ACC claims relating to non-fatal drownings
2012 - $732,452
2013 - $807,476
2014 - $1,182,316
2015 - $1,573,504
2016 - $1,350,082
New claims relating to non-fatal drownings for under 5's, cost of active claims for this age group over that period
2012 - 65 - $259,853
2013 - 53 - $245,083
2014 - 71 - $284,262
3015 - 84 - $306,580
2016 - 111 - $398,456
