Following the Directive 2014/89/EU, France completed its first round of maritime spatial planning (MSP) in 2022. It was based on participatory processes involving stakeholders as well as the wider public, using a dedicated online platform on three occasions between 2018 and 2021. Publics were consulted successively on the diagnostic, strategic and operational components of each Regional Maritime Spatial Plan, the so-called Documents Stratégiques de Façade (DSF). The authorities collected more than 4,300 online contributions. However, the authorities did not explain how the public contributions were integrated into the DSFs and how they were analyzed. This article explores this largely untapped, high-quality material. It seeks to understand who participated in the online consultation, what topics and issues were discussed, and what the outcomes were. Finally, this article draws some broader lessons about the participatory process and its inherent difficulty in transcending sectoral issues, and about the impact of participation on marine planning and the inherent difficulty of involving the wider public without rendering stakeholder consultation meaningless.