On the way to Ireland we'd travelled by the World's Largest Car Ferry. The return vessel was to be just a bit smaller. And faster. For we were going on The Dublin Swift - Irish Ferries's fast ferry which knocks off an hour and a half off the journey time.
Holidays. They always seem to involve rushing about. And it starts with rushing to the airport. Then rushing to security. Then rushing through the gate because security have held everyone up so long that your flight is on final call. Oh and there's an elderly woman pushing a pram in the way.
The £29 is the maximum price you'll pay for sail/rail to Ireland, and you can do it from pretty much anywhere in the UK - there are similar cheap offers for other ferry crossings to Ireland.