Caledonian MacBrayne's trouble-hit Finlaggan, whose inaugural sailing to Islay last month was cancelled because of engine problems, has now suffered mechanical problems with a new type of doors on its vehicle deck, causing further disruption.
The "clam shell" bow doors, which open sideways, have been out of action for almost a week, increasing the time it takes for vehicles to drive on and off.
Travellers were held up by nine hours when the door stuck last Tuesday. Since then, drivers have been forced to use the vessel's stern doors instead and turn around on board or reverse on to the vessel. The doors are the first of their type in a CalMac vessel.
The 300ft-long Polish-built ferry, which operates between Port Askaig on Islay and Kennacraig in Kintyre, can carry 550 passengers and 85 cars. It is CalMac's first new large ferry for a decade and Islay's first new one for 40 years.
Additional delays are being caused by unfinished work on passenger gangways at both ports, forcing them to use the vehicle ramp instead.
Islay hoteliers said such disruption could cost them dear. Graham Allison, owner of the Port Charlotte Hotel, said: "Any little thing which affects our peak season is a disaster.
"The worry is there is nothing to replace the Finlaggan if there is a problem, and we will not fill our rooms or get passing trade. We are classed as a fragile economy and most of us are trying to run year-round businesses. Anything that messes that up is just a nail in our coffins.
"The biggest problem is the banks do not support us - we cannot get an overdraft when we desperately need one because we do not get the business in the summer to back us up."
Mr Allison said businesses were doubly fearful about further problems with the Finlaggan after being left with a reduced ferry service last summer.
This followed the breakdown of the Clansman, which serves Barra, over its busiest period during the island's music festival, which led to one of the two Islay ferries being drafted in as a replacement.
Paul Graham, of the An taigh-osda at Bruichladdich hotel, said of the Finlaggan problems: "It is rather inconvenient and somewhat embarrassing considering the exorbitant cost of the vessel, which is like a cruise liner. What we really need is a more frequent service."
CalMac said it was doing everything possible to get the problems resolved. A spokesman said: "The service is still running, but it has slowed down a bit. We apologise for any inconvenience caused and share everyone's frustration when breakdowns of this kind occur, but the MV Finlaggan is a highly advanced and complex ship with around 500,000 components, so teething problems of this kind are not unusual."A spokeswoman for Caledonian Maritime Assets Limited (Cmal), the Scottish Government firm which owns the ferry, said: "Following the report of a technical fault on the forward ramp system on board MV Finlaggan on Tuesday, the vessel's crew and subcontractors addressed the problem and were able to close the ramp and bow door, allowing the ship to sail.
"The vessel will continue to operate using the stern ramp only, until replacement parts are sourced and fitted. Cmal is working closely with the shipyard, subcontractors and the operator to resolve this issue."