Enhancing maritime anomaly traffic monitoring is vital for national security, combating smuggling, and preventing human trafficking. In this work, we designed a self-powered drifting buoy (SDB) based on electromagnetic-triboelectric coupling for maritime anomaly traffic monitoring. The buoy shell adopts a self-righting structure combined with a low center of gravity to prevent capsizing and enable rapid self-righting. The integrated electromagnetic generator (EMG) within the SDB achieves self-powering functionality, eliminating the need for battery replacement or external power sources. In addition, the built-in corrective magnet establishes the SDB's directional reference at sea. Four integrated triboelectric nanogenerator (TENG) sensors detect wave directions through voltage generated during wave-induced tilting. Coupled with built-in satellite positioning and wireless communication modules, the SDB achieves real-time monitoring and transmission of wave directions and geographical positions to coastal terminals. By deploying multiple buoys as a networked array, coastal terminals can comprehensively analyze real-time vessel positions, moving directions, and speeds through wave data transmitted from each node. This buoy-based monitoring approach provides a novel self-powered solution for maritime traffic monitoring and management.