Police blame shallow water for jetboat crash

A jetboat that crashed and injured four people on a Canterbury river was driven into an area of shallow water, police say.

The crash happened about 10am yesterday when the boat was travelling downstream on the McCauley River, about 1km from the head of Lake Tekapo, Senior Constable Brent Swanson of Lake Tekapo Police said.

"The driver chose a braid in the river with insufficient water and the boat flipped once, landing upright in shallow section of the river," Mr Swanson said.

All four people on boat, aged in their 20s, were thrown from the boat.

People on another boat raised the alarm by cellphone and all four were taken to hospital, two by helicopter and two by ambulance.

Mr Swanson said one received head and back injuries, while another had a broken ankle and the other two received lower back injuries.

The four had been part of a group of three jet boats on the private trip.

The boat was moderately damaged in the crash, and had been recovered by other members of the expedition.

Maritime New Zealand is investigating.

- NZPA