I know there had to have been some Marines serving on naval bases or on US Navy ships, but did they play any combat operations role (significant or otherwise) in the land or air campaign in Europe or Africa? Did they have any involvement in the amphibious landings in the European/African theaters?
I realize that this is hardly an in depth response, but I doubt anyone could do much better than this listing of activities here. In effect, they were mainly in a planning and training role. http://www.shsu.edu/~his_ncp/USMCETO.html