The mapping of coastal hazards (coastal flooding, coastline recession) is based on both: knowledge of local phenomena and principles of natural risks prevention policy. During the development of coastal risks prevention plans, instructed by State services, hazards maps are the main subject of the discussions, sometimes leading to conflicts. These maps, crossed with stakes maps, are used to elaborate the regulatory zoning, one of the pieces of risks prevention plans. The process of regulatory zoning conception gives to the hazards mapping the main stage in the territorialization of coastal risks prevention plans. Thus the territorial authorities mainly see the hazards map as a pre-zoning, announcing urbanization restrictions and hazards mapping are influenced by opposing interests of stakeholders. For the State services, hazards maps are first a technical object, lowly negotiable. The debates, very technical, focused on hazards, hide risk prevention plans objectives. They thinly deal with mapping hypothesis linked to natural risks prevention national policy, based on national solidarity and sustainable development.