WITOIL (Where Is the Oil) is a multi-model Decision Support System (DSS) on-demand service that forecasts transport and weathering of actual or hypothetical oil spills in the global, regional European Seas, and in the selected coastal areas. WITOIL uses the MEDSLIK-II oil spill model forced by operational meteo-oceanographic services. The service has been further refined by using labelled image datasets from Sentinel 1, Sentinel 2 and Landsat 8 satellites to improve existing deep-learning algorithms and the AI-supported detection of oil spills. WITOIL is now an operational service in the iMagine-AI platform and interfaces with the existing operational marine pollution oil spill monitoring and modelling service running at CMCC. Relevant guidelines and documentation are also available to promote the service uptake. With WITOIL, Policymakers can better understand the problem, which will lead to the development of more effective policies, mitigation strategies, and further funding for technologies related to mitigating the environmental impact of oil spills.