MV Loch Seaforth developed problems with its engine control system on the Easter Bank Holiday Monday which led to a swathe of services being cancelled between Ullapool and Stornoway.
In the latest update, CalMac said its freight services departing from Stornoway at 10.50pm on Tuesday and from Ullapool at 2.50am on Wednesday were cancelled.
The 7am trip from Stornoway on Wednesday has also been cancelled, but the subsequent 10.30am departure from Ullapool is still in review, the update said.
CalMac said engineers have been investigating the fault, and additional sailings for essential traffic were operating between Uig and Tarbert.
Labour leader Anas Sawar, ahead of a trip to the Na h-Eileanan an Iar constituency, said people in the Western Isles “have been taken for granted by the SNP government.”
He commented on the state of the ferry service in South Uist where islanders are being offered a once a week service for the next month due to ongoing ferry breakdowns.
"The SNP’s neglect of the islands and their vital ferry services are coming home to roost with a broken down timetable that leaves islanders with only a once in a week lifeline to the mainland,” he said.
"That is simply unacceptable.”
Business owner Linda Johnson, who runs the Hebridean Guest House, Stornoway, said the latest ferry chaos has given her little hope for the months ahead.
“I am sick of it,” she said.
"Every phone call this morning has been ‘sorry, I won’t make it.’ It’s just not good enough.”
Ms Johnson said after a quiet winter she was looking forward to welcoming guests to get the spring season going.
"We had a decent week with Easter, we had some customers come over, but now this.
"I am not usually a worrier but I am worried for what’s to come over the next few months after today.”
Additional services were scheduled from Tabert on Tuesday at 8.40pm, and from Uig at 10.50pm to help with the backlog of traffic.
Passengers, however, were complaining on CalMac’s social media page that the boats were already full by Tuesday afternoon.
Three other large CalMac vessels have not been in service since the summer timetable began on April 1.
This is due to delays with the return of the MV Caledonian Isles, MV Hebridean Isles and MV Clansman because of more faults being discovered.
It is understood some parts to the ships are so old they are no longer manufactured.
SNP MSP for Na h-Eileanan an Iar Alasdair Allan said a number of his constituents said they were stranded on Monday.
He said the latest breakdown “does point to the continuing need for more vessels in the CalMac fleet.”
Scottish Conservative Highlands and Islands MSP Donald Cameron said the ferry chaos has “become so bad the whole country is now sitting up and taking notice of the dismal performance of ministers when it comes to our ferries".
He blamed the ferry chaos on “SNP neglect.”
A CalMac spokesperson said: “We are very sorry for the disruption and inconvenience that this technical fault is causing to our customers, and we are grateful for their patience.”