New Zealand's summer drowning toll hits 26 - already worse than last year's with two months still to go

New Zealand's shocking summer of drownings just got a lot worse with four people dying in the past 24 hours.

It brings the number of drownings in Aotearoa this summer to 26. That's already worse than the death toll for the whole of last summer and with two months left of this season, it's likely to rise even more.

Since Monday evening, there have been serious water-related incidents in north Canterbury, the Waikato River in Hamilton, Ngāruawāhia, Wenderholm in northern Auckland, Kai Iwi Lakes near Dargaville, and Mt Maunganui.

West of Hamilton in Waingaro, a 21-year-old man drowned on Tuesday afternoon while swimming at a waterfall in Waingaro River. 

One person who saw the man get into trouble while at the waterfall says she and her friends could barely see him.

"We just saw his bubbles and then just couldn't see him at all, he just disappeared," Katie Bell says.

She and her friends were enjoying the water in the shallows until an onlooker started shouting. 

"They were trying to find him, he jumped off the rocks, we told him to dive under the water and he tried to but he said it was too deep."

They tried everything they could to help before scrambling to call the police. 

At the river, the water starts off as shallow but quickly gets very deep and very dangerous. 

It's not the only serious recent water incident - police are also continuing to search for a missing man in the Waikato River. He went swimming with three others in central Hamilton on Monday but failed to return.

But General Community Manager for Hamilton City Council Helen Paki says the Waikato River is very dangerous and is urging locals and visitors to heed the signs.

"We don't encourage swimming in the river, and if they do we urge extreme caution," he says.

On Tuesday, his family worked alongside police to hold a vigil and they're hoping for a miracle.

This summer has seen a huge spike in water-related incidents with drownings over the summer period tracking ahead of past annual trends. 

Daniel Gerrard, the chief executive of Water Safety NZ, says there are about 25 drownings each summer - but we've already surpassed that for this year.

"I'm six months into this role, my first summer in this role and I'm a bit shaken up by it," he says.

He's urging all Kiwis to be vigilant in the water because everyone is at risk. 

"Take some time to look at the environment before you get it. If in doubt, just stay out."

It's the latest in a growing number of people dying in Aotearoa's water over the Christmas break period, including four drowning in the Manawatū River in Palmerston North.

A day they'll never forget and a wake-up call they hope will be heard by the whole country.