This thesis drifts into the ocean’s dark, turbulent depths to envision how urbanized seas erode landed geologics. Modernity has figured the ocean as an unknowable expanse opposed to land yet suffuse with extractable resources. In this way, the ocean has played backdrop for contested visions: as a space of biopolitical mobility as well as competition for natural resources and the policing of political borders. The 1981 United Nations Convention of the Law of the Seas (UNCLOS) attempted to reconcile these conflicting seascapes through the international legal principal of res communis, or “the common heritage of mankind.” Ultimately, this thesis portrays the ocean-as-commons through the Blake Plateau, a deep-sea landform 300 miles off the southeast coast of the United States currently subject to aggressive prospecting for rare earth minerals. The site acts as the locus of the Ocean Column Observatory (OCO), a multiscalar assemblage of decommissioned maritime infrastructure that supports vibrant relations between life and matter. Imagining new ways of inhabiting the ocean necessarily entails creating new representations attuned to watery ways of seeing landscape.