Laxo ferry terminal will be out of action during three days of linkspan maintenance work.
The work will begin after the 6.30pm crossing on Friday, 20th May, and regular services will resume at 7.10am on Monday, 23rd May.
Passengers travelling between Whalsay and Mainland during that time will need to use Vidlin ferry terminal, which is set to run to the regular timetable.
The SIC has reminded travellers there are no parking facilities at Vidlin and apologised for any inconvenience.
The work, which is weather dependent, is part of the council’s linkspan refurbishment project.
Improvements have already been carried out at Skerries, Symbister and Vidlin.