The entanglement of colonial power's cultural and material manifestations has been an important topic in anticolonial thinking. I tentatively term this the problem of relating the imperial imaginary and imperial reality. This essay focuses on the imaginary and real geographies of the eighteenth-century British maritime empire, using digital methods (custom named entity recognition and mapping) to compare place-names mentioned in maritime fiction and nonfiction with the movements of British ships. In Edward Said's terms, structures of reference are used to see the structures of attitude underpinning the material power of an increasingly global empire. I present four theses on the convergences and divergences between the imaginary empire of texts and real empire of ships: on the centrality of England in both, a shared colonial geography of fungibility, the imaginary's erasure of environmental and bodily restraints, and the imaginary empire's anticipation of, and even preparation for, real imperial domination.