Flight-free travel: How to get to the UK and Europe by ferry – The Irish Times
Irish Ferries - Wikipedia
LONDON to DUBLIN by train+ferry for £51.10 or €60
Reino Unido a Irlanda | Freightlink - Los expertos en Ferries de carga
A bridge across the Irish Sea is a ridiculous idea, but the ferries between Northern Ireland and Scotland are the most expensive in the UK – Slugger O'Toole
Brexit: Why Irish freight trade is avoiding Britain