The first mission of the Marine Corps. A Marine, trained at Sea School and assigned to the Marine Detachment on board ship. While most Marines at some time in their career will spend time on ship, only those Marines assigned as members of the ship”s complement earn this title. The insignia of a seagoing Marine is a gold seahorse superimposed on a gold anchor within a crimson lozenge. In 1998, all Marine Detachments on board ships were disbanded, thus ending a tradition that dated to 1775 and the first duty of the Marine Corps. (see USS Marine Association.)