Whalsay folk returning home on the ferry this evening (Wednesday) may be unable to take their cars due to reduced capacity.
The SIC said the Linga ferry was out of service on the Whalsay route due to an electrical fault.
While Fivla will operate between Laxo and Symbister, the SIC has warned of reduced vehicle capacity.
Public transport is being provided to meet each ferry arriving in Symbister, for any passengers unable to get their cars on board.
A normal timetable is hoped to resume tomorrow.
The SIC has apologised to passengers for any inconvenience.
Updates can be found by calling the Whalsay ferries voicebank on 01595 743973.