One thing I did notice, and I mention it because everyone I spoke to missed it, is that I always sit through all the closing credits. Many of the boats used in the film were actually present and participated in the evacuation and were noted in the credits. The one I remembered in the film was the "Mimosa" and I thought to myself "that looks like an old boat, I wonder if it was at Dunkirk?" It was along with a bunch of others.
I think one of the boats is actually currently used on the Thames for cruises. I would have to look up which one though.