Four people on the overnight ferry from Aberdeen to Shetland were injured after the ship encountered heavy seas off Fair Isle.
The Hrossey took a sudden roll to port at about 0430 BST.
The injuries were not serious. A number of cars were also slightly damaged, and a glass panel was broken by a sofa.
The ship carried on to Lerwick, arriving just after 0700 BST. Operators Northlink said the evening southbound sailing had been cancelled.