What about taking pets on the ferry?

Sail/Rail to Britain

It is mandatory for all pets to be on a leash at all times when not in a carrier/crate, either in the port area/terminal building or on board. All dogs on a lead must wear a muzzle if they are a restricted breed or if there is a risk of biting. Details of restricted breeds can be found here: Restricted Breeds list.

Check the relevant authority’s websites for full details of the requirements:

Ireland: https://www.gov.ie/en/publication/b76e9-brexit-movement-of-pets/

UK: https://www.gov.uk/guidance/pet-travel-to-and-from-great-britain