10 U.S.C. § 8061: Department of the Navy: composition

The Department of the Navy is composed of the following:(1) The Office of the Secretary of the Navy. (2) The Office of the Chief of Naval Operations. (3) The Headquarters, Marine Corps. (4) The entire operating forces, including naval aviation, of the Navy and of the Marine Corps, and the reserve components of those operating forces. (5) All field activities, headquarters, forces, bases, installations, activities, and functions under the control or supervision of the Secretary of the Navy. (6) The Coast Guard when it is operating as a service in the Navy.