Condor has warned it could see the longest spell of disruption to its services, as the islands braces for Storm Ciaran to make landfall on Wednesday night.
Gusts of up to 85 mph are expected on Thursday morning, forcing the ferry company to cancel all its high-speed sailing from 1 November to the following Tuesday (7 November).
A number of changes have also been made in the run-up to the storm hitting the English Channel.
A spokesperson for the company told us that the Liberation and Voyager sailings tomorrow (31 October) from Poole and St Malo will still run, but on 'revised timing and routes'.
The services between the Channel Islands and France the following day have both been cancelled. Passengers due to travel on those sailings will automatically be moved to Tuesday's service.
The Goodwill and Clipper are expected to travel on Tuesday and Wednesday (31 Oct & 1 Nov), with significant disruption 'likely' from Thursday.
Operations Director, Elwyn Dop says they are evaluating options for maintaining food and medical provisions across the week:
"‘We are proactively contacting passengers and freight clients to notify them of the likely changes and making plans as best we can, given the current forecasts. Our importance to the food supply chain is also understood so every effort will be made to ensure we continue.
"The weather is obviously unpredictable so we monitor forecasts constantly and suspect may end up making further changes over the period."

Ministers 'do not endorse' Inquiry comments in safeguarding meeting
Jersey FA over-50s walking football team are European Champions
Call for government to rebuild reserves against increased global uncertainty
"Please wear your poppy again this year with pride and remembrance"
Minister faces fresh criticism over workers' rights comments
Aquasplash to close for 'essential maintenance'
Jersey property market faces fresh pressure as interest rates rise
Stay safe celebrating Bonfire Night