Ferry services to and from Whalsay were disrupted on Monday after the Hendra was removed from service due to a burst pipe.
Engineers are on their way to inspect the vessel to carry out repairs, estimated to take around three hours.
The route has been served by the Fivla in the meantime.
Prior bookings on the Laxo/Symbister route were suspended.
Shetland Islands Council has apologised to passengers affected by this disruption.