Waterways Ireland is advising boat owners that essential maintenance work on the lock gates at Athlone have finished.
The lock was de-watered and closed last November to allow for work on the replacement of the mitre-posts on the upstream gates.
The structure on the bank of the Shannon just downstream from Athlone Castle was built in 1845 during the famine, and it has only been de-watered on two occasions since that time.
Waterways Ireland says it deliberately chose one of the quietest times on the river to carry out the work because the Athlone lock is one of the busiest on the navigation system.
Passage through the lock will be possible again from this morning. (Friday Feb 1st)