She was a star athlete with a bright future, but a freak accident in Whangamata Harbour has claimed the life of Waikato teenager Amie Louise Russell.

Amie, 15, of Morrinsville, died after becoming trapped under a yacht moored in the harbour yesterday afternoon.

The talented basketballer, who attended St Peter's School in Cambridge, was out paddleboarding when strong winds and current turned a day on the water to tragedy.

The area response manager for the Thames-Coromandel police, Senior Sergeant Graham Shields, said police extended their sympathies to Amie's friends and family.

"Police are assisting the Waikato Regional Council's harbourmaster's office in investigating what has occurred," he said.

"At this stage it appears two people were on a paddleboard crossing Whangamata Harbour when they were caught in a strong outgoing current about 2pm."

Shields said strong winds and current forced the board under a moored yacht.

One person was able to jump , but Amie became submerged for several minutes.

"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," Shields said.

The Waikato community is in a state of shock at the passing of the popular basketballer.

Amie was this year made co-captain of the Waikato under-17 basketball squad after previously making the New Zealand under-16 team.

Her coach of two years, Waikato Basketball community basketball manager Anthony Corban, is heartbroken at the loss.

"I'm just in a state of shock," he said.

"She was a very, very well-loved young athlete by all her peers and coaches.

"She was an amazing athlete who had a huge future ahead of herself."

Amie worked hard last year to move from the reserves to the New Zealand under-16 team, he said.

"Very typical of the kid she is; she outworked the players and made the team."

She had played four years above herself in the national under-19 team last year and would be missed immensely across the sporting and wider community, Corban said.

"She was such a lovely person, very respectful of her team-mates and adults, a hard worker and very valued team-mate," he said.

"It's tough times for everyone."

Corban understood the accident had been a "one in a hundred" situation.

"She was such a strong athlete; it shocked me that she drowned," he said.

Amie's family had been at the water's edge when lifeguards and St John paramedics arrived.

Police cordoned off the area, which was packed with people on a hot afternoon.

Whangamata harbourmaster Steve Wise said the drowning was the first fatality in the harbour in the nine years he had been working there.

"It sounds like a freak sort of an accident," he said. "I have never heard of something like this happening before.

"She just got hooked by the current and went under one of the yachts that was moored in the harbour."