Cruise lines publish a check-in window rather than a single arrival time, and it is worth planning your transfer around the start of that window rather than the middle or end of it, particularly for a first cruise from a given port. Embarkation halls can have queues that build through the afternoon as more coaches and cars arrive, so an earlier arrival within the check-in window often means less time standing in line with luggage, even though the ship itself will not leave any sooner.
The return journey deserves the same planning as the outbound one: disembarkation mornings are usually busy at every UK cruise port, with many passengers leaving within a similar window, so booking your homeward transfer in advance rather than trying to arrange one on the day means you are not competing with a terminal full of passengers all looking for a ride at once. Confirming an approximate collection time with us ahead of the sailing, and updating it if the ship's actual disembarkation schedule changes, keeps the whole return leg as predictable as the outbound one.