The use of offshore bars to fight beach erosion, dating back to the 90 th , was based on the fact that they represented a substantial reservoir of sediments. That theory turned out to be irrelevant, as beach nourishment requires coarser grain sizes. However, the essential role these bars can play in wave mitigation was demonstrated by recent studies. Hence, working on reinforcing existing bars or even adding extra bars is a convincing approach, for they constitute a line of defence with no visual impact and are therefore environment-friendly. The method offers the added benefit of tapping abundant fine sands, easily available offshore, to build up the bars. All these assumptions should, of course, be systematically checked, the purpose of the exercise being to assess, through mid-term and long-term bathymetric evolution simulation, the consequences of the implementation of offshore bar nourishment and define the best location. The second aim of this study is to define a parameterization of the screenplay of the weather condition over a season, one year or a decade in an appropriate number of climatic events for the simulation.