The term 'ONE SERVING ON A SHIP' can be summarized as a MARINE, which is a six-letter word. A MARINE is a member of the United States MARINE Corps, an elite branch of the U.S. military that specializes in amphibious operations. Marines are responsible for providing security on ships and other vessels, as well as engaging in combat operations on land and sea. They are highly trained and disciplined individuals who serve with honor and courage.