Marines are part of the Department of the Navy. They share many traditions in common with the Navy. The language/terminology they use is Naval (Army says "latrine," Navy/Marines say "head," etc.). I was in the Navy for most of the 1970s and we always had a Marine Detachment abroad ship. Marines don't have their own medics, but use Navy Hospital Corpsman. Navy and Marines are very familiar with each other and often work closely together.