Final answer:
The relationship between the Sec Nav and the CNO/CMC involves the civilian leadership and oversight provided by the Sec Nav, as well as the military command and advisement roles of the CNO and CMC over the Navy and Marine Corps, respectively.
Step-by-step explanation:
The relationship between the Secretary of the Navy (Sec Nav) and the Chief of Naval Operations (CNO)/Commandant of the Marine Corps (CMC) reflects a significant aspect of the U.S. military's organization and command structure. The Sec Nav is a civilian and serves as the head of the Department of the Navy, which includes both the Navy and the Marine Corps. Reporting directly to the Secretary of Defense, the Sec Nav is responsible for policies and control of the naval services but is not in the direct operational chain of command.
The CNO and CMC are the highest-ranking military officers of the Navy and Marine Corps, respectively. They are members of the Joint Chiefs of Staff and advise the SecNav on matters concerning their specific services. While the CNO is responsible for the command, utilization of resources, and operating efficiency of the naval forces, it is the responsibility of the CMC to oversee the same within the Marine Corps. These relationships ensure the effectiveness and readiness of the naval services and maintain the necessary balance between civilian oversight and military command.