This work examines the naming logics of maritime geographical features (such as rocks, sandbanks…) using the island of Ouessant as its field site. While official charts from the French Naval Hydrographic and Oceanographic Service (SHOM) display certain toponyms, the historicity, usage, and spelling of these names have been questioned in previous linguistic studies (Madeg & Pondaven, 2004). Drawing on a participatory mapping approach, this research documents contemporary toponymic practices and highlights the multiplicity of names that coexist in this space, while analyzing the power dynamics that influence which names are selected and visible over others. By engaging with critical approaches in toponymy and cartography, the study offers an interpretive framework for understanding dynamics of visibility, and sheds light on the tensions between cartographic efficiency, linguistic standardization, and the recognition of vernacular knowledge, within a coastal space that remains both fertile and relatively underexplored by such perspectives.