You are right about Megabus timetables being hidden. I have seen the route Manchester-Dublin advertised. When I tried it for Wednesdays both ways in June no times came up. I am mildly curious as to what days it runs but won't look any further for now in case the service does not start until for example later in July.
That has been running for some time now and AFAIK runs daily. It is a connection to/from the overnight Irish Ferries sailings, the same one that Eurolines uses. Megabus service is much quicker as Eurolines has multiple stops and a rest stop.
Arguably in this case it being quicker may not be such a good thing. From Manchester it departs 1h30 later but arrives in Holyhead earlier leaving passengers with a 3 hour wait in the terminal for the sailing
In the other direction it gives a very early arrival at 03.25 into Manchester with Eurolines 2 hours later.
Not sure why it is not giving the journey for your date unless they have not added the dates yet or have dropped the service?
There's a Manchester to Dublin service tonight. It departs at 21.10, runs via Holyhead, and arrives at 05.55.
http://uk.megabus.com/JourneyResult...inboundPcaCount=0&promotionCode=&withReturn=0
To be precise it is a Manchester to Holyhead Megabus service with ferry connection as a foot passenger to Dublin Port only.
Onward bus to Dublin City is not included in the Megabus fare and would be required as the ferry terminal is a very long walk through the Dublin port complex to anywhere approaching civilization.