Large-scale marine protected areas (LSMPAs) are growing in prominence as an area-based conservation strategy that places vast areas of the ocean (more than 150,000 square kilometres at a time) into formal protection. While LSMPAs are lauded for their conservation potential—for example, their ability to protect entire marine habitats and the ranges of highly mobile marine species—they also fulfil other political, social and economic functions. This chapter considers the role of imagination in the oceanic bordering practices of LSMPA designation. It demonstrates how LSMPAs are mobilised as resources by powerful actors to promote visions of progress tied to national identities centred on continuing connection to the ocean. In doing so, it illustrates how there is more at stake in the establishment of LSMPAs than conservation and marine management alone. The oceanic bordering agendas associated with LSMPAs not only redraw ocean maps, but also reinforce and renew national identities in relation to ocean space.