Taking a ferry from Wales to Dublin.

Why not return the car in Holyhead, that seems like the easier option. Hertz has an office in Holyhead.

The Liverpool to Dublin ferry no longer runs (for passengers) as of a few months ago. You will have to go to Holyhead.

Depending on which car rental company you use you should be able to drop it at Chester or maybe Llandudno.

Then train straight from Chester or Llandudno Junction.

EDIT- To be there by 5pm you would need to be on the breakfast time ferry, so would really need to stay the previous night in Holyhead. The early afternoon ferry gets you in too late.

Thanks for the feedback. It is funny, I tried to drop a car at Holyhead on the Kayak app and it did not work. Or at least it was not offered as a spot to drop a car. I will check and make sure that Hertz has an outlet in Holyhead. I think we will rent in Cardiff and do a little driving. any other thoughts are more than welcome!

That is one of the problems of using third parties such as Kayak. They will only offer what they can make money on, not necessarily all options. Hertz actually have two offices at Holyhead- both at the port, rather than in the town.

I am going the opposite way but I have a reservation to pick up a car from Enterprise at the port in Holyhead. So I would think you could return somewhere there if you end up on that ferry.

You don't say how long you plan to be in Wales as that obviously has a bearing on how much you can do.

The Enterprise web site says that the Holyhead Office is closed on Sunday and closes at 12 noon on Saturday.
The same is true of Hertz except they close at 1pm on Saturday.

The same Enterprise hours are true of both Chester and Llandudno Junction.

But at Llandudno you could return the car on Saturday morning, leave your luggage at a Stasher type place, visit Conwy and/or Bodnant Gardens then a train to Holyhead.

Likewise for Chester return the car in the morning, luggage at Stasher (opposite the Railway Station), explore Chester for the day and then an evening train to Holyhead.

If you wanted to explore Cardiff and then Pembrokeshire instead you could take the Saturday lunchtime ferry from Fishguard to Rosslare, then the short train or bus journey (or taxi) to Wexford for overnight then Sunday morning train to Wexford.
Wexford is one of those cities of Ireland which tourists often neglect to visit, for no reason other than they haven't heard of it.

Yes you could continue to Dublin on the Saturday but this is a chance to visit somewhere else.

Thanks everyone! I think we have settled on getting to Chester and spending a couple of nights there. Have found a day tour from there. Then taking the train from Chester to Holyhead and then the ferry to Dublin. I think the fast ferry might be operating by May 11. I am wondering if anyone can suggest a nice in town hotel in Chester. I suppose I should go to the England forum!

Thanks!!