<P> Horn of Africa Operations </P> <P> Throughout the Global War on Terrorism, the US Marines have supported operations in Africa to counter Islamic extremism and piracy in the Red Sea . In late 2002, Combined Joint Task Force--Horn of Africa was stood up at Camp Lemonnier, Djibouti to provide regional security . Despite transferring overall command to the Navy in 2006, the Marines continued to operate in the Horn of Africa into 2007 . </P> <P> The Department of the Navy, led by the Secretary of the Navy, is a military department of the cabinet - level U.S. Department of Defense that oversees the Marine Corps and the Navy . The most senior Marine officer is the Commandant, unless a Marine officer is the Chairman or Vice Chairman of the Joint Chiefs, responsible to the Secretary of the Navy for organizing, recruiting, training, and equipping the Marine Corps so that its forces are ready for deployment under the operational command of the Combatant Commanders . The Marine Corps is organized into four principal subdivisions: Headquarters Marine Corps (HQMC), the Operating Forces, the Supporting Establishment, and the Marine Forces Reserve (MARFORRES or USMCR). </P> <P> Headquarters Marine Corps consists of the Commandant of the Marine Corps, the Assistant Commandant of the Marine Corps, the Director Marine Corps Staff, the several Deputy Commandants, the Sergeant Major of the Marine Corps, and various special staff officers and Marine Corps agency heads that report directly to either the Commandant or Assistant Commandant . HQMC is supported by the Headquarters and Service Battalion, USMC providing administrative, supply, logistics, training, and services support to the Commandant and his staff . </P>

Are the marines part of the us navy