While the integration of Geographical Information Systems (GIS) and Multicriteria Decision Aiding (MCDA) has attracted increasing interest from researchers in recent years, due to the wide array of applications that can benefit from GIS as well as the different types of decision problems and various models that can be used through MCDA, plenty of opportunities of integrating GIS and MCDA remain. We present the result of such an opportunity in the form of a tool that is currently used by the Naval Hydrographic and Oceanographic Service in France. Furthermore, this tool may used in conjunction with other GIS-MCDA applications with a single decision maker, multiple decision makers or even where the decision has a hierarchical structure.