For more than half a century, the defining characteristic of submarine warfare has been invisibility. Whether or not the system is combat-ready, the signal to rivals is unmistakable: China is closing the technological gap in undersea warfare. If submarine captains doubt their invisibility, the psychological effect could constrain operations, regardless of whether the Chinese system achieves perfection. Electronic and Cyber WarfareAttacks designed to disrupt, spoof, or disable China’s detection algorithms and communication networks. The question is no longer whether AI will shape undersea warfare, but whose algorithms will dominate the depths.