Terry Schutz, managing director of South Australian company Tough-As Products, said there was nothing unusual about the trip until the early hours of Tuesday morning.

“The waves were smashing the ship and once or twice the vessel leaned heavily to the left and everything flew off the tables in the rooms,” he said.

“There would have been no-one on that ship that was asleep after 5am.”

Mr Schutz’s suspicion that there had been movement on the parking decks was confirmed when the ship docked at Devonport.

“Most of the passengers guessed that something had happened because the crew were calling passengers individually,” he said.

“The cars had just slammed into each other because of how rough it was.”

His company ute sustained significant scraping on both of its sides, but Mr Schutz felt he “got off lightly” compared to the damage on other cars and trucks.

He estimated that between seven and 10 other vehicles on parking deck five were also impacted.

The owners of the affected vehicles did not disembark the ship until about 11am after the damage had been assessed and insurance arrangements discussed.

A spokesperson for the Spirit of Tasmania confirmed on Tuesday morning that both vessels experienced choppy conditions overnight.

“Both Spirit of Tasmania vessels were delayed into Melbourne and Devonport because of rough weather and high winds,” the spokesperson said.

“Some cargo and passenger vehicles shifted on the overnight crossing from Melbourne to Devonport. Any damage to vehicles is yet to be determined.”

No damage to the ship was recorded.