Waiting for the Holyhead to Dublin ferry ...

On Friday Emi, the Wonder Dog and I arrived in Holyhead six hours early for our ferry crossing to Dublin. I really hadn't intended to be quite so early, but with the vagaries of what the traffic might be like on the M6 we'd left London first thing in the morning to arrive in plenty of time. As luck would have it we encountered no problems on the roads, but arrived half an hour too late to make the earlier sailing. So what could we do with six hours to spare in Holyhead?