I heard that for shit details, the Navy calls in the Marines. Also, if they were worth their salt, they would be a branch of their own, not part of the Navy.
You can't expect those nancy's to get their dungarees dirty. If we were a branch on our own, who'd chauffeur us around to all the shit details. Plus, when an enemy sees Navy ships coming they're like "ooooh, not the Navy". Then they crap their pants when a batallion of Devil Dogs hit's the beach looking for a fight. If you've never seen a Marine amphibious assault, you've missed a fantastic display of military prowess. I may be biased, but only a little.
Ronny said it best:
"Some people spend an entire lifetime wondering if they made a difference in the world, but the Marines don't have that problem."
There's a reason we're the "first to fight".