In coastal areas around the world, actors are responding to multiple global changes by implementing adaptation plans, often confined within a single-focal perspective with few explanations of targeted changes and cross-scale interactions. To better anticipate the raising coordination issues and the potential feedbacks generated by adaptation in these complex social-ecological systems where governance scales overlap, we used the robustness framework (Anderies et al. 2004; Anderies 2015). We analyzed a case study along the Languedoc coastline in southern France, where governance is organized in multiple jurisdictions which we considered as interlinked adaptation situations. We identified three interacting changes impacting adaptation: demographic growth, climate change, and large-scale political changes, such as decentralization. We used the examples of land-use planning and coastal management to illustrate the major coordination challenges facing the implementation of adaptation plans in coastal areas by various intertwined communities. In the example of land-use planning, adaptation is impacted by miscoordination between multiple sectors that all rely on a shared resource, land, thus putting more pressure on the decision-makers to make explicit trade-offs between multiple issues. Coastal management illustrated how emerging adaptation strategies created new interdependencies in the system and how these were hardly considered due to confusion in the devolution of responsibility between multiple jurisdictions. In both examples, using coupled and evolving robustness diagrams was helpful in revealing renewed fragilities, foreseeing consequences of adaptation in inter-related decisional contexts, and promoting collective action to redefine the boundaries of adaptation situations and their coordination to cope with converging changes along coastlines.