P&O Ferries have announced that the 10.30 am sailing from Larne to Cairnryan has been postponed until 12.30 pm due to adverse sea conditions.
The ferry operator says that the company will then take a decision about the crossing.
The next sailing is scheduled for 1.30 pm. Passengers are asked to check in by 12.30 pm.
Stormy weather forced the cancellation of Irish Sea crossings last night.