There seems to be a 2:00 hour journey-time with Stena and €284 return fare which appears to be a FastCat job - I've never managed to catch it. I found it using http://www.directferries.ie/
which is not my usual site. Normal journey-time is 3:30 hours.
Any suggestions for somewhere to break the journey from Holyhead to London around the half-way mark? Preferably not a soulless motorway service station...