Vietnam leads Southeast Asia with the largest submarine fleet, operating a total of nine vessels that significantly strengthen its maritime defense. Indonesia follows in second place with five submarines that serve as a core component of its naval capabilities. Singapore ranks third, supported by four technologically advanced submarines that enhance its strategic deterrence.
Below the top three, Malaysia maintains two submarines as part of its long-term maritime security strategy. Myanmar operates a single submarine, marking an early step in expanding its naval modernization efforts. While smaller in scale, these fleets still represent each country’s commitment to safeguarding regional waters.
The Philippines and Thailand do not yet field active submarines but are preparing notable upgrades. The Philippines is planning to acquire two submarines to improve its maritime defense posture. Thailand is currently in the process of purchasing three submarines from China as part of its broader military modernization program.
