A Maritime New Zealand investigation has found a Shotover Jet boat driver's ''lapse of judgement'' caused the boat to hit a rock face in October.
None of the boat's seven passengers was injured when it clipped a canyon wall near Edith Cavell bridge on the Shotover River, causing minor damage to the boat's stern.
Maritime NZ spokeswoman Sophie Hazelhurst said the finding had been backed up by the company's own investigation.
It identified a need to improve Shotover Jet's ''system of providing additional monitoring of drivers after their initial training, particularly during the early stages of their operational driving''.
The company had made an ''appropriate response'' to the incident, and the agency would monitor its progress in improving driver monitoring.
The driver had completed 122 hours of training since joining the company in May and had passed a driving assessment by the Queenstown harbour master, Ms Hazelhurst said.
Shotover Jet, owned by Ngai Tahu Tourism, is the only company permitted to operate in the Shotover River canyons.
Ngai Tahu Tourism southern regional manager David Kennedy said such incidents were ''quite rare'' because of the extensive training it gave its drivers.
The company was required by law to provide 50 hours of commercial driver training, but did 120 hours.
When incidents did occur, the company took them ''very seriously'' and was happy with Maritime New Zealand's findings.
''We deal very closely with Maritime New Zealand at all times, and we're always looking to improve our safety and systems wherever we can.''
The driver, who was stood down pending the investigation, had returned to his role.
The company had 13 drivers, some of whom had been with the company for more than 10 years, he said.
However, normal staff turnover meant their range of experience changed from year to year as new drivers were occasionally taken on and trained, he said.