Some west coast ferry services face disruption at the height of the summer holidays as CalMac struggles with a shortage of ships.

The publicly-owned operator said one of its largest vessels MV Caledonian Isles - which has been out of action for 18 months - is still not ready to return to service.

Another major vessel, MV Lord of the Isles, needs work on its engines, while the chartered catamaran MV Alfred is due for annual maintenance.

CalMac is redeploying several ferries across the network in a bid to maintain services, but has warned that sailings to Arran, Islay, Mull, South Uist and Colonsay will be disrupted.

The reshuffle will, however, allow sailings from Ardrossan to Arran to resume next week when the 41-year-old ship MV Isle of Arran returns to the route.

The North Ayrshire town has been without a ferry service for six months, since the arrival of MV Glen Sannox which is too large to fit the Ardrossan facilities, and sails instead from Troon.

A CalMac spokesperson said having three major vessels out of service in July meant some disruption was unavoidable but it was taking steps to give communities as much capacity as possible.

The spokesperson said : "Both MV Alfred and MV Lord of the Isles require the works they'll be off service for, and we are doing the best we can to maintain service levels and meet capacity requirements on all islands with the vessels available to us during this period.

"We are grateful to local communities for their support as we've worked through a complex set of circumstances and apologise to those who will see services affected between 7 and 21 July."