The Coastguard and Grampian Police were called out to retrieve a car from Johnshaven Harbour on Friday night.
The car was found floating in the harbour by Johnshaven residents after they heard a “loud bang”.
Police and lifeboat crews were then called to Johnshaven Harbour at around 11pm after a blue Vauxhall Astra was spotted in the water alongside fishing boats.
The car was badly damaged as rough waters smashed the vehicle into the harbour’s walls, before it finally went under.
Grampian Police said an investigation is under way following the incident, which took place at around 11pm on Friday. The sea was so rough that Montrose RNLI had to drive their inshore lifeboat round by road and launch from the village slipway, rather than approach by water.
The small lifeboat was used to locate the vehicle, which had sunk to about a metre and a half below the water line.
Grappling hooks were then used to attach a tow rope, and the car was then hauled back to shore at around 3.30am on Saturday.