The Battlefield Band, as Jeri says, recorded a song entitled The Beaches of St. Valery on their album "Rain, Hail or Shine" (Temple Records in Europe, Rounder Records in the USA).  It is a modern song written by Davy Steele ("Elizabeth Clare" is, I think, just a tune coupled with it rather than a writer's credit) based on his father's and uncle's experiences in the evacuation of Dunkirk and its aftermath; Steele senior was rescued, but his brother, who was a little further south at St. Valery, was taken prisoner and spent the war as a POW.  Part of the point of the song is that those captured were heroes quite as much as those who remained free to fight again, but were often not treated as such; apparently Steele's uncle eventually emigrated to Canada, partly because of the way he felt he had been neglected in his native land.  I haven't heard it and so cannot speak for the tune, but I believe that he wrote that too, which would certainly explain why it's different from the pipe march.

Malcolm