Iains, you have swapped from Airlines to Ferries in a very short space.

Ryan Air require a passport as ID, Aer Lingus, Flybe require a Photo ID.

Irish Ferries and Stena Line merely ask for the names of people travelling in the vehicle when you book the trip, that is PRIOR to your journey.

Never, when travelling by sea, have I been asked to verify the nationality of the people travelling in my vehicle, which has been up to 17 people on one occasion, and each year there have been at least 10 people.