An ageing ferry which has not sailed since January last year could be out of service for another four months, operator CalMac has said.
The 32-year-old MV Caledonian Isles was forced out of action 18 months ago, leaving a hole in the timetable for the west coast ferries.
CalMac has now said the vessel will return to dry dock for further repairs – which will likely take between eight weeks and four months – prompting a re-think of the winter timetable.
The repair bill for the ferry, which has been side-lined from the Arran route since January 2024, has already risen to nearly £11m.
Calmac said MV Caledonian Isles will enter drydock in Leith in the coming days for works to repair an issue with “instability in pitch response”.
The ferry will have its shaft lines removed for further investigation.
This will take a minimum of eight weeks including sea trials.
If this doesn’t solve the problem – the retrofitting of a new system to improve the accuracy of the pitch input will be attempted. This would take four months.
Duncan Mackison, CalMac CEO, said: “Based on the current prognosis, we could be in a situation where MV Caledonian Isles returns in September in a best-case scenario or November in a worst-case scenario.
“However, we intend to publish winter timetables soon and aim to give communities and customers certainty about service levels and vessel deployment during that period.
“This is a complex process as we need to develop this plan whilst factoring in an annual overhaul schedule that will see a fleet, which is another year older, spend a record of number of days in planned maintenance.”
The ferry operator’s winter timetable runs from 20 October to 26 March 2026, and its entire fleet undergoes annual maintenance between September and May each year.