A hospital spokeswoman said all five were discharged on Monday night but she would not specify what injuries they had suffered.
A 67-year-old man with a pre-existing medical condition and suspected broken leg, and a boy younger than 5 with head injuries, had been transferred to the hospital by air late Monday afternoon.
The three people taken by road were a woman in her 40s with a suspected broken arm, a girl in her early teens with a leg injury and a boy in his teens with head and possible back injuries.
Community Constable Bruce Dow said the police were liaising with Environment Canterbury and would report to Maritime New Zealand.
It would be Maritime New Zealand's decision whether to lay charges based on the information supplied by police, Const Dow said.
On Monday, Const Dow said one of the boat drivers, who came from Christchurch, had broken boating rules by travelling in a clockwise direction.
