CalMac has paid out more than £850,000 to passengers for cancelled sailings over five years, new figures indicate.
It includes £215,000 spent by the operator in the first four months of this financial year.
The figures were published in response to a freedom of information request by the Scottish Liberal Democrats.
Customer rights claims include money for meals, accommodation, transport and compensation as a result of cancellations.
Business owners in the Western Isles have previously told STV News of the impact on trade and tourism caused by ongoing breakdowns, suspensions and cancellations.
There has also been ongoing scrutiny of the decision to award a contact to build two new ferries to Ferguson Marine, with the vessels significantly over-budget and overdue.
MSPs are set to debate the issue, with calls for the Scottish Government to set out a strategy to tackle problems on the ferry network.
It comes after a BBC Disclosure documentary which uncovered a leaked dossier suggesting that the process of awarding the contract to Ferguson Marine was rigged.
CalMac stated that many of the participants involved at the time are no longer employed with the operator, adding that “initial internal searches have found no evidence in our files to support the allegations presented to us”.
Willie Rennie, the Scottish Liberal Democrat economy spokesperson, warned of the impact that the delays in the construction of the vessels is having upon island communities.
“The bill for cancellations and compensation is soaring because the Scottish ferry network is in such a state,” he said.
“The last year has seen new levels of havoc. Aging boats are breaking down and it is having a huge impact on islander, tourists and travellers.
“Delays in the construction of two new ferries by Ferguson Marine mean that island communities are still being put on hold by the Scottish Government.”
Rennie insisted that his party would introduce a “wider economic strategy” to ensure that government projects represent value for money.
He said: “Scottish Liberal Democrats would tackle delays, breakdowns and cancellations by giving the ferry network the funding it has been starved of for years and allowing communities to plan ahead for replacing creaking ferries.
“We would also introduce a wider economic strategy that ensures government projects, such as Ferguson Marine, represent value for money.”
Transport Scotland has said that over £2bn in support has been provided by the Scottish Government to the country’s ferry network since 2007.
The operator has indicated that there are more vessels and more routes running “than ever before”.
A spokesperson for Transport Scotland said: “The vast majority of CalMac ferries run on time and to schedule but breakdowns and delays are not acceptable.
“That’s why we’ve invested to provide additional capacity on the Clyde and Hebrides routes.
“We are also continuing to work on procuring more vessels, while the four new ferries we have ordered are being built.”
A spokeswoman for CalMac said: “Our customers have been affected by higher than usual levels of disruption in recent years, including significant upheaval due to the Covid pandemic. This has led to an increase in the number of claims.
“Our customers are at the very heart of what we do and we aim to provide the best service we possibly can. When sailings are disrupted or cancelled, we make sure that passengers are fully aware of their rights to claim back costs they incur.”