The increasing complexity of maritime risks and threats requires accurate and timely identification for environmental and human safety. Satellite observations enable comprehensive surveillance of large maritime areas, which is essential for detecting and responding to environmental changes and potential threats. The Horizon Europe project EURMARS aims to develop and validate a multi-purpose observation platform to enhance detection capabilities for various risks and threats. This paper introduces a novel Earth Observation (EO) algorithm based on Object-Based Image Analysis (OBIA), employing a You Only Look Once (YOLO) -v9 model to process data from open-access satellites (Sentinel-1, Sentinel-2, Landsat 8, 9) and video from the microsatellite NEMO-HD. Automatic Identification System (AIS) data are used to ensure comprehensive monitoring and validate the method’s results. Satellite imagery with AIS data integration is a critical element of the vessel tracking methodology, significantly improving the accuracy and reliability of maritime surveillance. Real-life demonstrations have confirmed the method’s effectiveness in enhancing maritime security and facilitating early detection and response to threats.