Irish Ferries has been forced to cancel sailings on its Ulysses ship due to technical problems.
A statement released by the company said that a problem with a propeller shaft requires immediate attention at the dry dock.
The Ulysses normally covers the Dublin to Holyhead route. Irish Ferries said that the ship is likely to be back online by the middle of next week.
Irish Ferries has been hit by bad luck in recent weeks, as the company was forced to cancel all sailings to France on board its new W. B. Yeats ship because of delays in manufacturing.