IR theory rests on territorial assumptions which shape our understanding of the nature of the state, the rise of the state system and the very concept of the international. The following paper asks, what if we moved away from a fixation on bounded territory to consider the influence of oceans and the maritime sphere? Humanity’s interaction with the sea has shaped history from the earliest known polities and early modern history, in particular, saw the rise of several great maritime powers. It was these movements across oceans which essentially shaped the modern world we know today, yet, the maritime sphere is virtually absent from IR theory. Security scholars may discuss piracy or projecting naval power, but this article aims to provide a more comprehensive treatment of incorporating a view of the oceans into IR theory. An examination of early modern maritime empires shows how the British empire developed by seeking to control ocean flows and circulations.