KEY POINTS:
Large pieces of ice are keeping jet boats off the Shotover River near Queenstown.
Chunks of ice the size of car tyres were floating down the river forcing Shotover Jet staff to cancel some trips, the Otago Daily Times reported.
Shotover Jet operations manager Simon Thew said the ice formed upstream in Skippers Canyon, where air temperatures sat at -5.82degC just before noon yesterday.
Wind chill meant the temperature on a jet-boat travelling at up to 70kmh dropped to about -20degC, he said.
Icicles nearly 2m long were hanging from rocks in some parts of the canyons, and boats regularly hit chunks of ice as they made their way up and down the river, he said.
This made a loud noise but did not damage boats, and staff checked the river was safe each day before beginning tourist trips, he said.
- NZPA
