This chapter draws from the example of fisheries to unpack the politics of ocean borders in relation to both resource extraction and environmental protection and in view of state territoriality. The first section bordered-in territoriality focuses on fisheries and conservation within the territorial seas and EEZs, where ocean borders are associated with state’s sovereign rights. Second, it takes the space of high seas as the bordered-out territoriality, emphasising the high seas as the commons and the ways the state performs its territoriality without claiming sovereign rights via distant-water fisheries. Third, overlapped territoriality is used to address the disputed maritime grey zones between different states and how fisheries have played a key role in bordering-up a cooperative space of sovereign rights for fishing. Although this chapter focuses on discussions about fisheries, the critical points addressed actually extend beyond this activity and connect to debates regarding other marine resources in general.