Since there are officially no Marines in Trek, there are no official Marine overlays. There are, however, a couple of Rapid Reaction Team overlays in the TNG Players' Guide. (One flaw in the published overlay is the idea that an infantry officer automatically gets promoted to Lieutenant - the equivalent of an Army or Marine Captain. I can tellyou as a former infantryman that this ain't gonna happen - the two ranks below that are vital to the training and experience of an officer. )