<p>I agree with what 69 is saying for the present, but in the past the MM’s definitely “served”. During WWII, the USMM had the highest fatality rate among any service branch (about 4%), most of them aboard Liberty ships.</p>
<p>Of course most of this was in '41 and '42 before USMMA was established in 1943 but you get the point.</p>