Just 12 miles separate mainland UK from Northern Ireland at its closest point. That point happens to be in Scotland, so it will be no surprise that all but 1 sailing to Northern Ireland from the UK sails from Scotland.
There is currently up to 13 daily sailings from Scotland to Northern Ireland, that’s spread across 2 routes, Cairnryan to Belfast and Cairnryan to Larne. The other sailing from the UK, goes from Liverpool to Belfast and sails twice a day, once during the day and once overnight.
The Troon to Larne ferry that was operated by P&O Ferries closed in September 2015.
The fastest crossing is the P&O Cairnryan to Larne fast ferry which only sails in the peak service months (April to September) – the sailing takes just over and hour and with drive on drive off ferries is one ferry service that is perhaps in real terms quicker than flying.
The newest ferry service to launch on the Irish sea goes from Cairnryan to Belfast, it was launched in 2012 and is operated by Stena Line. The route replaces Stena’s old Stranraer to Belfast ferries and is serviced by the biggest ferries ever to sail between Scotland and Northern Ireland, Stena Superfast VII and Stena Superfast VIII, these ships are currently the newest and most modern ferries to Northern Ireland.
You last option on sailing to Northern Ireland and only option from outside of Scotland, is the ferry from Liverpool to Belfast. This sailing from England takes 8 hours, so is much longer crossing, you can choose to sail through the day or there is an option to sail overnight. On these sailings you can check yourself in a cabin and simply sleep your way through the crossing.