The ferry routes in 2009 were broadly similar to today with a few key differences:
Stena Line's Belfast route sailed to Stranraer in Scotland (since November 2011 the Scottish port is Cairnryan - a few miles seawards along Loch Ryan from Stranraer)
There was a seasonal route from Larne to Troon operated by P & O (since discontinued)
There is also a route from Belfast to Douglas (Isle of Man) - Isle of Man Steam Packet Company. Back in 2009 it only sailed to Belfast in the Summer and used to sail to Dublin at Christmas but in recent years there has been a sailing to and from Belfast (to/from the IOM) just before Christmas and again just before the New Year. There were also a few sailings from Larne to Douglas around TT races time on the Isle of Man.
Another major change is that the longstanding route from Dún Laoghaire to Holyhead - the Dublin Airport of its day ceased after operation on 9th September, 2014 (nowadays all ferries go into Dublin). Dún Laoghaire was known and travelled through by generations of emigrants and visitors.
There was also a route from Cork to Swansea which ceased around 2011 and a route from Rosslare to Roscoff (France).
I think that is all that is different but others may be able to confirm if there's anything I missed.
If you wished to look at sailing schedules (which are generally more or less the same as today) you could go to the likes of the Wayback Machine, type in the ferry operator's website and browse.
I hope the foregoing information is helpful.
Stena Line's Belfast route sailed to Stranraer in Scotland (since November 2011 the Scottish port is Cairnryan - a few miles seawards along Loch Ryan from Stranraer)
There was a seasonal route from Larne to Troon operated by P & O (since discontinued)
There is also a route from Belfast to Douglas (Isle of Man) - Isle of Man Steam Packet Company. Back in 2009 it only sailed to Belfast in the Summer and used to sail to Dublin at Christmas but in recent years there has been a sailing to and from Belfast (to/from the IOM) just before Christmas and again just before the New Year. There were also a few sailings from Larne to Douglas around TT races time on the Isle of Man.
Another major change is that the longstanding route from Dún Laoghaire to Holyhead - the Dublin Airport of its day ceased after operation on 9th September, 2014 (nowadays all ferries go into Dublin). Dún Laoghaire was known and travelled through by generations of emigrants and visitors.
There was also a route from Cork to Swansea which ceased around 2011 and a route from Rosslare to Roscoff (France).
I think that is all that is different but others may be able to confirm if there's anything I missed.
If you wished to look at sailing schedules (which are generally more or less the same as today) you could go to the likes of the Wayback Machine, type in the ferry operator's website and browse.
I hope the foregoing information is helpful.