Divers are inspecting the new Glen Sannox following the discovery of a crack in the ship’s hull.
The brand new vessel only began operating in January after being delivered almost seven years late and costing more than four times the original contract price.
All of the Glen Sannox’s Saturday sailings have been cancelled while the MV Alfred will operate an additional service.
CalMac said it would provide an update on Sunday’s sailings once a dive team had carried out a full assessment.
The ship had been operating since January between Troon in South Ayrshire and Brodick in the Isle of Arran.
The vessel was removed from service of Friday after a crack was found on a “weld seam close to the waterline”.
The ferry operator said reports that the boat had hit the harbour or that water was leaking into the car deck were “categorically untrue”.
However, CalMac advised that a “very small amount of water” had entered part of the rear of the ship near the steering gear.
Additional sailings have also been added between Lochranza in Arran and Claonaig in the Kintyre peninsula.
A statement from the ferry operator said: “We apologise for the disruption, and our port teams and customer engagement centre will be working hard to contact affected customers.”
