The Fire Service and ambulance officers were taken to the injured by jetboat, Acting Senior Sergeant Craig Dinnissen, of Dunedin, said. Worksafe and Maritime New Zealand had been told and would investigate.
Four of the five people have been discharged this morning, but the 12-year-old remained under hospital care for "precautionary reasons", Shotover Jet manager Clark Scott said.
"We are confident that she's ok, but we're all acting in a very, very cautious manner at this stage," he said.
"We are doing all that we can to continue to offer our support to those that were on the boat and their families and/or friends that were travelling, and of course, our driver that was involved in the incident."
The boat, one of seven the company uses, hit a rock, he said, but it was "too early" to say at this stage what exactly happened.
The company was working with investigators, and had brought in an independent investigator of its own, to establish how the crash occurred, he said.
Shotover Jet, which is owned by Ngai Tahu Tourism, has carried more than three million passengers since being launched in 1965. In April last year the company gained international attention after taking the Duke and Duchess of Cambridge on a trip.
The company briefly suspended operations last October after a jetboat carrying 10 people hit a rock.
An earlier version of this story ran with an incorrect headline stating the girl injured in the accident was in a critical condition. This was not correct.
