History of the Seagoing Marines

Together with the U.S. Navy, the U.S. Marine Corps is part of the naval service of the nation’s military. Because it’s a naval service, the Marine Corps is comfortable in operating at sea as part of the Navy and Marine Corps combat team. In fact, since 1775 and until 1998, units of Marines frequently served aboard Navy ships as part of what’s called a detachment. A traditional Marine detachment on a Navy ship served many purposes, including providing security and defense.

     The presence of Marines aboard Navy ships has a history going back to the U.S. Navy’s forbears, the British Royal Navy. Since the birth of the Corps in 1775, seagoing Marines have routinely served aboard Navy ships. Traditionally, Marine detachments, or MarDets, on Navy ships such as battleships, cruisers, and aircraft carriers serving as security and even attack forces as well as in various naval-specific ceremonial functions. Typically, two officers and from 35 to 55 enlisted troops made up a Navy ship’s MarDet.

      In the decades leading up to the end of World War II, Marine detachments aboard Navy ships were used to great effect by those ships’ commanding officers. MarDets operated the confinement brigs aboard assigned Navy ships and conducted attack operations against the enemy ashore. After World War II, the duties of Navy shipboard Marine detachments evolved. Toward the end of their presence, MarDets were used to safeguard “special weapons,” a euphemism for nuclear-tipped missiles.

     According to Navy historians, many Marine officers and enlisted personnel looked at Marine detachment duty as career-enhancing. For Marines at sea, shipboard life offered an opportunity to see the world as well as to hone amphibious-combat skills. Marines assigned to Navy shipboard MarDets had serious responsibilities as part of their ships’ manpower. Marine detachments are trained to fight shipboard fires as well as to go ashore and rescue American citizens.