Hundreds of passengers on board The Waverley paddle steamer were left stranded when it broke down in the middle of the Clyde.
The ship was stuck between Greenock and Helensburgh for several hours but later made it to Greenock.
Waverley Excursons Ltd said it was due to a problem with boiler controls and it regretted the inconvenience and disappointment of passengers.
Specialist engineers will now try to repair the ship.
Tommy Barnes, who was on board the steamer, told BBC Radio Scotland: “There are worse places to be stranded but after a while it does start to wear thin.”
The Waverley set off from the centre of Glasgow at 10:00 on Saturday, and it was due to stop in Helensburgh, Dunoon and Rothesay.
However, the vessel began experiencing some difficulties at Helensburgh, where it was delayed.
Passengers were told that it would continue its journey to Rothesay but it would no longer be stopping at Dunoon.
It is understood the vessel was carrying some people planning to spend the day at the Cowal Highland Gathering, near Dunoon.
All passengers were also given the option of leaving the boat at Helensburgh.
Mr Barnes said: “After that we set sail and we sailed for approximately 15 to 20 minutes before all engines seemed to cut out.”
Waverley Excursions said it tried to book coaches to transport passengers who disembarked at Helensburgh, but none were available.
Instead passengers were advised to continue their journeys by train and apply to have their fares reimbursed.