Force structure has to be measured through guaranteed availability rather than the number of hulls visible on paper. Five aviation ships could reliably provide two flight decks, while three well-deck ships could guarantee one dock for amphibious operations. A four-boat ballistic-missile-submarine force follows the same logic by keeping one submarine on patrol while another remains available. A requirement for two deployed capabilities cannot be met by buying only two ships, because refit, training, and recovery continually remove hulls from immediate use.
Notable Point · 3:00:03-3:01:27
Why deployed requirements need extra hulls
Maintenance and training cycles mean five flight decks may be needed to guarantee two, just as four ballistic-missile submarines sustain one patrol.