The world’s first deep-sea mining (DSM) project has witnessed the commercial development of plans to extract copper and gold from deposits 1600m deep in the waters of offshore Papua New Guinea (PNG). Viewed as ‘experimental’ and ‘uncertain’ by its critics, it has afforded both controversy and resistance. This paper critically analyses the multifarious strategies that the industry’s apologists use in order to respond to environmental concerns and to manufacture consent. It draws upon extensive primary data conducted at the ‘Solwara 1’ DSM project in Papua New Guinea in order to highlight three different ways in which DSM is legitimised by its contractor, Nautilus Minerals. All of these draw upon the spatio-temporal materialities of the deep-sea. In the first instance, the corporation shifts its responsibility away from the ‘social’ realm, instead placing it on a ‘nature’ that is constructed as violent and unruly. Secondly, it emphasises both the relatively short life-span and areal footprint of its mining operations. Finally, Nautilus emphasises the ‘placelessness’ and remoteness of the deep-ocean by claiming that its operations ‘have no human impact’ despite the presence of proximate small island communities. These strategies are part of a corporate understanding that is aware, rather than ignorant, of contemporary geopolitical formations that include geologic and non-human actors and operate dynamically in space and time. Taken together, the paper shows the ways in which resource spatio-temporalities come to matter for the types of CSR practices and narratives that emerge in the context of deep-ocean space and time.