I'm sure I'd class the journey by bus because the reference to the necessary and proportionally tiny boat or eurotunnel crossing would be seen as obvious, unnecessary and annoying.
- not at all! i went by foot, took a bus, went by foot, took a train, went by foot, took an elevator, went by foot, took the plane, went by foot, took a taxi, and then by foot
For crossing the Channel, definitely not. A very special exception can be made with prior arrangement for those with disabilities that made entering & leaving their vehicle too cumbersome, but they aren't going to ride this kind of bus.