This looks rather like tree. See wiki: http://wiki.openstreetmap.org/wiki/Tag:route=ferry ... Please remember to connect each end of the ferry route to a way on land. Do not combine two different parts of the route when approaching land ...
I had not seen that they were two ways. I have now combined both ways, but there is a validation error on a long distance route "Via Romea Francigena - part Grean Britain", but it was already broken. It was sloppy anyway as I expect it need to be "Via Romea Francigena - part Great Britain" I'll see whether I can fix it.