Last spring when I rode from Germany to England, I was planning on taking the ferry from Oostende to Dover. Then I found out en route that there is no longer ferry service out of Oostende. It wasn't a problem though as I just adjusted my route and headed to Dunkirk.
I had no problems at all at Dunkirk. Told them I was on a bike, they didn't bat an eyelash. Bought my ticket, went to use the facilities, and I discovered that they have showers free to use. Excellent.
I guess they have them for all the truckers who come through transporting goods from Britain to the continent. I was very happy to take an unexpected, hot, indoor shower.