okay, cool and sneaky at the same time on the logo. you can't tell from the shots. thanks for providing the link to a big badge.
Your welcome. Some versions of the symbol vary from the original quite a bit, but I like the idea of placing the 3 planet logo from UFOP inside the original USMC badge, where Earth used to be. Makes the most sense to me.
I have created Marine vessels with some different trademarks to set them apart....
First, they have a general mix of hull patterns, between a Defiant type (with green hues instead of blue) and the Sov. Most patterns are two tone, light pattern on the dorsal side, darker on the ventral side. This represents that the hulls are designed with modern materials and armor, all the way down to the smallest shuttle.
Also, almost all ships have some kind of armament. This is a force multiplier.
Third, they all carry the SFMC symbol, and the numbers/letters are a bit different. You will see "Starfleet Marine Corps" in the banner. There is no name for smaller ships, and they rarely if ever list the ship they are assigned to...instead they carry a plain numerical designation. Also, most ships in the Marine fleet have reduced illumination and even have a different color for their deflectors...yellow instead of blue.
Finally, the designations are different. Instead of NCC you will see specific ship class designations, like "BB" and the like.
For instance, the Battleship "Spartan", Ares class reads something like this....
SMS Spartan, BB-123
SMS stands for "Starfleet Marine corps Starship", whereas I contend USS stands for "United federation of planets Starfleet Starship". BB is the designation for a Battleship, and all Battleships have that designation. Since this is a new registry, the ship numbers actually represent the total number of that class in order.
This makes it very easy to identify Marine ships compared to Starfleet vessels.