Progress in Signals and Telecommunication Engineering Jie-Wei Name: Zhang 15 2 2026 https://doi.org/10.6025/pste/2026/15/2/49-63 https://www.dline.info/pste/fulltext/v15n2/pstev15n2_1.pdf Reliable identification of tactical engagement transitions in continuous underwater telemetry is critical for automated monitoring and situational awareness, yet it remains challenging due to severe bandwidth constraints, environmental noise, and complex multivariate sensor dynamics. This study develops and evaluates a robust multimethod change point detection framework designed to accurately identify these operational transitions. We applied seven complementary statistical approaches, CUSUM, PELT, binary segmentation, Bayesian inference, kernel detection, ruptures style segmentation, and multivariate Mahalanobis analysis to a comprehensive 12,000-observation telemetry dataset. Dimensionality reduction via principal component analysis and multivariate distributional metrics were utilized to capture coordinated, system level state shifts. Results demonstrated exceptional cross-method convergence and temporal precision. Six of the seven methods localized the tactical engagement onset exactly at the reference boundary, while the online CUSUM monitor detected the transition within a negligible five-second delay. Furthermore, segmentation methods successfully recovered the complete engagement interval, accurately identifying both onset and termination boundaries. Multivariate and kernel analyses confirmed that the transition represents a profound, systemwide distributional shift rather than an isolated sensor anomaly. By integrating diverse detection principles, the proposed framework provides strong cross validation, ensuring the identified boundaries are genuine features of the underlying telemetry dynamics rather than algorithmic artifacts. Ultimately, this multimethod approach offers a highly reliable, automated mechanism for distinguishing routine patrol from event related tactical states, significantly enhancing real time decisionmaking, reducing operator workload, and improving mission reliability in complex underwater sensing environments.