A Christchurch man remains in a serious condition in hospital following a "freak" jet ski accident on a South Canterbury lake.
The crash happened at the head waters of Lake Aviemore, near Kurow, about 5.30pm on Sunday.
The 45-year-old driver was travelling about 70kmh when he hit shallow rocks, suffering serious pelvic and rib injuries.
The man was airlifted to Christchurch Hospital and was in a serious, but stable condition in intensive care today, a hospital spokesman said.
Witness Jordan Ryder, who did not want to reveal the man's name, said the man was on the jet ski for only about 30 seconds before the crash.
"He wasn't even out for a jet ski. He was just going to put it on the trailer. It was a bit of a freak accident really."
The man had spotted the shallow rocks, which protruded from the bank about 5 metres, but was unable to turn away or jump off the craft in time.
He hit the handlebars before being thrown onto the rocks and into the water. The man was an experienced jet skier and knew the lake well, Ryder said.
"It's deceivingly shallow.
"He's clipped a rock underneath and stopped the jet ski in its tracks.
"It was a blindspot - the rocks would have just come out of nowhere."
- The Press