Blair Nathan Deasy (50) was also ordered to pay a $750 fine at his sentencing in the Queenstown District Court yesterday.
He was prosecuted by Maritime New Zealand following last year’s incident and convicted on a charge of dangerous activity involving a ship.
The victim was one of four children taking turns on an inflatable biscuit being pulled by his boat.
She was at the back of the boat, feeding out rope, while two other children were riding on the biscuit.
Her leg got caught in the rope and she was flipped into the lake.
In a media statement, Maritime NZ Southern compliance manager Domonic Venz said instead of killing the boat’s engine and pulling the girl back onboard, Deasy reversed.
The victim’s leg was caught in the propeller, and she suffered serious lacerations to both legs.
She was unable to walk for months.
Mr Venz said that before leaving shore, Deasy had prioritised safety for everyone onboard, checking there were life jackets and having a briefing with the children explaining safety matters.
However, understanding the risks and turning the boat off would have avoided the accident.
"In high pressure situations, it is critical skippers understand how to avoid situations that can put themselves, their passengers or others at risk.''
