Sail & Rail

[comcor]

My turn for a Sail-Rail question...

I'm going to need to get from Cardiff to Wexford shortly, although I think I can get collected from Rosslare, so I won't be tied to being on the overnight ferry.

I have a couple of questions

• On the Arriva Trains Wales website, the date I want is just beyond the threshold. Unlike Irish Rail, this doesn't seem to go one day at a time, but instead jumps several weeks in one go. It moved yesterday to just short of the date I want. Does anyone know how long I'll be waiting until they move it again?
• Regarding reservations, it says "Yes. Reservations are compulsory on Stena Line and Irish Ferries services and on all Advance train journeys. A place will be booked on the ferry for you at time of purchase. Failure to obtain a reservation may result in you not being allowed to board the vessel." This is a bit confusing to me. Is booking the ticket online enough to have the reservation or is there another step?
• If I choose to pick up the tickets from the vending machine in Cardiff Central Station, do I just get a single rail-like ticket that specifies Cardiff to Rosslare via Fishguard? Is that enough to present myself for check-in on the boat?