Who is responsible for organizing the Navy's onshore bases?

The Commander, Navy Installations Command (CNIC) is responsible for organizing the Navy's onshore bases. This role encompasses a wide range of duties related to the management and operation of naval installations across the United States. CNIC ensures that these bases are well-maintained, adequately resourced, and capable of supporting both operational and quality of life needs for Navy personnel and their families.

The secretary of the Navy oversees the Navy and Marine Corps but does not engage directly with the day-to-day management of onshore installations. The Chief of Naval Operations has a broader focus on naval operations and combat readiness, rather than specific installation management. The Commandant of the Marine Corps is responsible for the Marine Corps and its installations, not the Navy's bases. Therefore, the CNIC’s dedicated focus on naval installations makes it the correct choice for this question.