India’s submarine modernization roadmap aims to enhance its undersea capabilities by 2035, integrating diesel-electric, nuclear-powered ballistic, and attack submarines to counter threats from China and Pakistan. The Indian Navy is focused on replenishing its dwindling fleet numbers, with notable projects like P-75 and P-75(I) advancing indigenous construction and advanced technologies. The SSBN program, crucial for national security, is anchored by the operational INS Arihant and expanding with new-class submarines. While challenges remain in achieving high indigenous content and meeting stringent requirements, this comprehensive strategy is designed to secure India’s maritime interests and project power in the Indo-Pacific.