"People at the scene pulled her from the water and commenced CPR which was continued onshore by arriving medical and ambulance staff but this was ultimately unsuccessful.
"At this point we would like to again urge people to take the time to identify what tides and currents are doing and never underestimate the power of moving water. Also be aware of the limits of your own abilities in the water and those of the people with and around you."
EARLIER: A teenage girl has drowned after her paddle board was swept under a boat by a strong current and wind at Whangamata yesterday.
Senior Sergeant Graham Shields said emergency services were called to the wharf off Beach Rd at Whangamata Harbour about 2pm after reports of a paddle boarder trapped under a boat.
"At this stage we can't confirm the exact circumstances but it appears that the boat was moored at the time and a teenage girl on the paddle board was swept underneath by a combination of wind and a strong current," Mr Shields said.
People at the scene rescued the girl and began CPR.
The resuscitation was taken over by medical and ambulance staff but the girl could not be revived.
"A lot of people worked really hard to keep her alive and our thoughts are with them and her family," Mr Shields said.
Some of the girl's family had been at the scene and they were being supported by police.
Police were now trying to establish what happened.
"We will work with the Waikato Regional Council harbourmaster to establish exactly what occurred and see if anything can be learned to prevent repeat incidents in the future," Mr Shields said.
Whangamata harbourmaster Steve Wise said by the time he arrived on the scene, St John staff, firefighters and police were all working to save the 15-year-old girl.
They finally got a pulse and stabilised her enough to get her to the ambulance, he said.
It is understood the girl was airlifted to hospital but died en route.
Mr Wise said the girl's mother rushed to the scene. He helped comfort one of the girl's friends, who had also been out on paddle boards in the main channel about 100 metres off shore.
"It appears the girl has fallen off and the current has caught her, and she was sucked underneath a 26ft yacht moored at the wharf," he said.
Mr Wise said the girl's friends got her back on her paddle board and a passing boat helped bring her to shore.
The girl had been wearing a belt pouch with a lifejacket, he said.
Mr Wise, who has been harbourmaster for two years and deputy harbourmaster for seven years, had been coming to Whangamata for six decades.
"I have never heard of anything like this before," he said.
"It's an absolute tragedy."
A Hamilton police source said he understood the teenager was not a local, and her name would not be released until next-of-kin were informed. Additional reporting NZME