10 U.S.C. § 8035: Vice Chief of Naval Operations

There is a Vice Chief of Naval Operations, appointed by the President, by and with the advice and consent of the Senate, from officers on the active-duty list in the line of the Navy serving in grades above captain and eligible to command at sea. The Vice Chief of Naval Operations, while so serving, has the grade of admiral without vacating his permanent grade. The Vice Chief of Naval Operations has such authority and duties with respect to the Department of the Navy as the Chief of Naval Operations, with the approval of the Secretary of the Navy, may delegate to or prescribe for him. Orders issued by the Vice Chief of Naval Operations in performing such duties have the same effect as those issued by the Chief of Naval Operations. the Vice Chief of Naval Operations shall perform the duties of the Chief of Naval Operations until a successor is appointed or the absence or disability ceases; or if there is a vacancy in the office of the Vice Chief of Naval Operations or the Vice Chief of Naval Operations is absent or disabled, unless the President directs otherwise, the most senior officer of the Navy in the Office of the Chief of Naval Operations who is not absent or disabled and who is not restricted in performance of duty shall perform the duties of the Chief of Naval Operations until a successor to the Chief of Naval Operations or the Vice Chief of Naval Operations is appointed or until the absence or disability of the Chief of Naval Operations or Vice Chief of Naval Operations ceases, whichever occurs first.