Maritime NZ is investigating after a motorboat driven by an allegedly intoxicated man hit a bank on the Clutha River, sending the boat spinning into trees and injuring three people.
A 37-year-old man was taken to Dunedin Hospital with serious facial injuries following the crash about 4.30pm on Saturday.
Two others were treated at Clutha Health First after the trio presented to the health centre about 5pm. The driver walked away uninjured and did not attend the health centre, a police spokeswoman said.
They were lucky the incident was not more serious, she said.
"The boat hit a shingle bank and spun off into some willow trees," she said.
The crash occurred on the river between Stirling and Balclutha.
A 52-year-old man sustained head injuries and a 44-year-old woman suffered a dislocated shoulder.
"Alcohol was involved," the spokeswoman said.
"None of the four were in life-jackets and there appeared to be excessive speed involved as well.
"Police have referred it to Maritime NZ because we have real concerns about what the people were doing."
The boat was a 5m to 6m aluminium vessel with a 130-horsepower motor, she said.
Police were informed of the incident by staff at the health centre.
A spokesman for Maritime NZ said it was aware of the incident and was making initial inquiries.
"We have no further details to provide at this point," he said.