This paper presents the recent developments of an Optimal Path Planning - Decision Support System (OPP-DSS). The designed framework is based on multi-objective optimization algorithms providing a set of Pareto efficient solutions repre- senting a trade-off among mission objectives. Meteorological and Oceanographic (METOC) and Automatic Identification System (AIS) vessel traffic data are integrated and exploited inside the planning process to improve surveillance in piracy risk areas. Tests in an operational scenario with real-world data provide indication of the effectiveness of the approach.