Coastal and marine areas represent an increasingly important and relevant action space for spatial planning. However, to a large extent marine (or maritime) spatial planning has emerged separately from terrestrial spatial planning, constituting its own epistemic community. In particular, previous studies indicate that Marine Spatial Planning often follows an expert-driven resource management rationale focused on sea-use regulation. This paper examines practices of Marine Spatial Planning and Integrated Coastal Zone Management at the German North Sea coast. The paper focuses in particular on the engagement of spatial planners with these practices and their perception of their role therein. We seek to understand what form spatial planning at the coast and at sea currently takes and how this might develop in the future in response to current and anticipated policy developments. We argue for the necessity of a communicative, cross-sectoral approach to spatial planning at sea, providing a spatial vision for the future that extends from the Exclusive Economic Zone to encompass both the coastal waters of the federal states and the land-sea interface in a substantive manner.