Britain will lead the development of three advanced sensor systems for unmanned underwater vehicles as part of the AUKUS partnership. This decision resulted from a week of testing of cutting-edge equipment conducted by alliance members—Australia, Britain, and the United States—during the Maritime Big Play exercises in San Diego, California. The new sensor systems are designed to detect potential underwater threats and will be installed on unmanned underwater vehicles. The development of such technologies is considered an important part of expanding military-technical cooperation between the three countries under the AUKUS defense pact, concluded in 2021. The San Diego testing allowed partners to evaluate modern equipment in real conditions and determine directions for further development of underwater surveillance systems. Such sensors are considered a key element of the strategy for ensuring maritime security, including protection of underwater infrastructure and monitoring of activity in coastal waters. Strengthening capabilities in underwater surveillance aligns with AUKUS's broader goals of developing advanced defense technologies, including nuclear-powered submarines and artificial intelligence systems. Britain's leadership in this particular project underscores the distribution of technological competencies among alliance member countries.