Dunedin man Iain Sweetman said his Jeep ended up in Otago Harbour about 9.10am after he swerved to avoid the family of what were believed to be Paradise ducks.
When he braked, the rear of the Jeep locked, causing the vehicle to spin and roll over a bank into the water, he said.
Damaging the Jeep was the lesser of two evils.
"Well, I’m not happy. The old Jeep was a great joy but I’d probably be feeling a lot more cut up if the ducks had been killed.
"You get to know them pretty well when they’re marching the chicks around everywhere this time of year."
As the vehicle fell about 4m into the harbour, he had a momentary thought about whether the tide was in or out, he said.
Mr Sweetman had been working on the Jeep as a summer project, and remained philosophical about restoring it, saying that would just take a bit longer now.
A police spokeswoman said Mr Sweetman was out of the vehicle before emergency services arrived.
He was assessed by St John staff at the scene.
