A captain in the Marine Corps’s pay grade is O-3, whereas a captain in the Navy is an O-6, as one shining example. And as those of us that have spent time in uniform can attest, having a good understanding of military ranks in the order of authority for our own branch doesn’t necessarily mean you know how the rank structure looks in the sister branches.Ĭonfusion about the order of military ranks can be made even worse from branch to branch by the common use of some easily-recognizable rank names (like sergeant or captain) for entirely different pay grades. Everybody recognizes the ones that commonly show up in movies like sergeant, captain, or admiral, but where they fall on the pecking order of different branches isn’t all that clear. Before you get to basic training, most people don’t have a very thorough understanding of military ranks, let alone the ability to put them in order.