Pet cabins have proved popular with passengers and their four-legged friends, according to NorthLink.
The Hjaltland and Hrossey each have two pet-friendly cabins, which were introduced in July.
Since then there have been 490 pet cabin sales across these two boats and the Hamnavoe, NorthLink managing director Stuart Garrett told a Shetland external transport forum on Wednesday.
There were also 78 occasions where there was a waiting list for these rooms, added Mr Garrett.
The success of the cabins has led to plans to introduce up to three additional pet cabins each on the Hjaltland and Hrossey.
Mr Garrett said: “I would like to thank everyone who has given us very positive feedback on the pet cabins.”
The cabins have vinyl floor coverings instead of carpet and a water bowl provided, as well as a dog treat.