Amie Russell was holding on to the paddleboard of her brother Hayden when she lost her grip and was dragged by the current under a boat moored in the Whangamata harbour.
A coroner's inquest in Hamilton today into the Morrinsville 17-year-old's death revealed that her board was swept to one side of the boat, while she was stuck under the boat on the other side, unable to free herself - probably because of her leg rope becoming wrapped around the boat's keel.
Earlier, Ms Russell had been standing on the paddleboard, while her friend Natarsha O'Flaherty was sitting in front of her. The pair were among a group of friends who had decided to paddle out into the harbour.
Ms O'Flaherty said they decided to travel between two boats that were moored about 3m apart after being swept down by a strong current.
However, while they were in between the boats, the pair were knocked off their board by strong wash created by a passing boat.
"I'm not sure if she has jumped or fallen but when she went in, the board went one side [of one of the boats] and Amie the other," Ms O'Flaherty said.
Ms Russell's brother Hayden, now 15, was with the group and saw his sister putting her leg rope on as she held on to a fishing boat.
He paddled over and she grabbed hold of his board. They then paddled over to a mooring boat, Clara; Hayden was holding on to the boat's anchor rope while his sister was holding on to his paddleboard.
"Amie then lost grip of the board and went towards the side of the boat, going under the water," Hayden said. "Amie's paddleboard was on one side of the boat with Natarsha on it and when Amie came off my board she was on the opposite side of the boat. I got off my board and went into the water to help."
He first tried to find her on the side where the paddleboard was, before heading to the back of the boat.
Another friend in their group, Cameron Dromgool, paddled over and dived into the water.
On the second dive, he found Ms Russell and tried to hold her head above water, but the leg rope was pulling too tight.
David Wenham was on a paddleboard with his 6-year-old son when he heard someone say "she's gone under". He dropped his son off and paddled over before diving under the boat to try to free Ms Russell. He was able to undo the rope leash and she immediately rose to the surface.
CPR was performed by rescuers, including surf lifesaving staff, and a pulse was found, but she died a short time later.
Senior Constable Garry Paton said it was likely that Ms Russell's leash got caught around the boat's anchor rope; however, those who helped to rescue her from the water believed the rope had become wrapped around the keel of the boat.
Ms Russell's father, Darrell, said his daughter was a strong swimmer. He and wife, Catherine, had taught all three of their children to swim from an early age. The couple encouraged their use of paddleboards, buying five for the family to use.
Although they were all very water-wise, they were completely oblivious to a moored yacht being a hazard.
He said while a sign warning paddleboarders of the danger could be an idea, he wasn't sure it would be of any use as it has to be seen by paddleboarders, most of whom can enter the water from anywhere.
Coroner Gordon Matenga reserved his decision.
On a personal note, he acknowledged the positive impact Ms Russell had had on people, as he knew of several in the basketball fraternity who had been rocked by her death.
Outside court, Darrell Russell said the 14 months since his daughter's death had been incredibly hard but he hoped there would be lessons from the incident so such a thing didn't happen to others.