This study systematically examines the temporal evolution of technology convergence and applicant network structures in the field of South Korean unmanned maritime systems, based on patent data collected from 2011 to 2022. The analysis is conducted across three distinct periods using centrality and network metrics. Findings reveal a progressive deepening of technological convergence, with aircraft (B64U), detection (G01S), and ship structures (B63B) emerging as core technologies. Network visualization illustrates an initial phase of limited interconnectivity, transitioning towards enhanced cluster integration and centralization over time. Applicant analysis indicates that individual applicants dominated during the first period, while technology sharing and collaborative networks expanded from the second period onward, underscoring the growing significance of industry-academia cooperation. The convergence of maritime unmanned systems with unmanned aerial vehicles, autonomous control, and surveillance technologies highlights a shift towards complex, integrated systems. These findings suggest the need for strategic policy support that fosters multi-stakeholder collaboration, promotes open innovation, and encourages knowledge-sharing across sectors. The results offer a foundational basis for future roadmap planning, ecosystem development, and investment prioritization in the evolving maritime unmanned systems domain.