The visual conquering of the Portuguese sea

Since the 1982 United Nations Convention on the Law of the Sea (UNCLOS), coastal countries have been able to claim sovereignty over the continental shelf by scientifically demonstrating ‘natural prolongation’ between their emerged and submerged surfaces. This paper examines how techno-scientific and politico-legal visions and visualizations shape Portugal's pursuit of sovereignty over the deep ocean. Drawing on fieldwork with scientists, technical experts, and instittuional representatives involved in Portugal's extension project, as well as analysis of policy documents, press coverage, visual and exhibition materials, it interrogates what the diverse images involved in the extension efforts do. It explores how the geological and geophysical evidence required by UNCLOS is produced through and rendered into visual representations. The paper shows how technoscience naturalises territorialisation and argues that images are part of the arsenal that enables ‘peaceful’ conquest — a visual conquest that reveals and conceals the turbulent imperial histories beneath. Yet as they seduce and enchant, images also conquer back. As they flatten the deep-sea, transforming its complex materiality into a surface upon which new territories are inscribed, Portugal's oceanic claim emerges not just through images, but as image. Visuality thus becomes a battleground of oceanic territorialisation unsettling Portugal's maritime future and inviting decolonial re-depthings of the sea.