In the United States, the Secretary of the Navy is the civilian head of the Department of the Navy. He was a member of the President'sCabinet until 1947, when the Navy, Army, and newly created Air Force were placed in the Department of Defense and the Secretary of the Navy was placed under the Secretary of Defense. Naval and Marine personnel informally refer to the Secretary of the Navy as "SECNAV."
The Secretary of the Navy is responsible for, and has the authority under Title 10 of the United States Code, to conduct all the affairs of the Department of the Navy, including: recruiting, organizing, supplying, equipping, training, mobilizing, and demobilizing. The Secretary also oversees the construction, outfitting, and repair of naval ships, equipment and facilities. SECNAV is responsible for the formulation and implementation of policies and programs that are consistent with the national security policies and objectives established by the President and the Secretary of Defense. The Department of the Navy consists of two uniformed Services: the United States Navy and the United States Marine Corps.
The Navy Secretariat
The Office of the Secretary of the Navy and its subordinate officials are known collectively as the Navy Secretariat. Other members of the Secretariat include the Under Secretary of the Navy and the Assistant Secretaries of the Navy (ASN).
And be it further enacted, That a principal clerk and such other clerks as he shall think necessary, shall be appointed by the Secretary of the Navy, who shall be employed in such manner as he shall deem most expedient.
In case of vacancy in the office of the secretary, by removal or otherwise, it shall be the duty of the principal clerk to take the charge and custody of all the books, records and documents of the said office.
The Assistant Secretaries report to the Under Secretary of the Navy, the Navy's number-two civilian officer.
The Assistant Secretary was the Navy's number-two civilian until 1940, when Congress established the position of Under Secretary of the Navy, who was given oversight of the Assistant Secretary's activities.
James V. Forrestal, later Secretary of Defense, was the first to serve as Under Secretary; he held the post until 1944, when he became Secretary of the Navy.