The digital age and recent developments in historical lexicography bring exciting new possibilities for the study of metaphor, in relation to both the scale of analysis and the identification of linguistic and conceptual patterning that was previously hidden from view. This article illustrates this by using the “Metaphor Map of English” to investigate metaphor in the semantic field of moving water. The Metaphor Map offers an unparalleled overview of the place of metaphor in the recorded language history of English and across semantic space, as it takes as its source of data the entire Historical Thesaurus of English, itself largely based on the Oxford English Dictionary. This semantic field (labelled ‘Tides, waves and flooding’ in the Metaphor Map) is a productive source of metaphor, and has been since the Old English period, and is also, though less commonly, the target of metaphor. It reveals a clear picture of the complex interrelationships between semantic categories and the ripples of metaphor development over time.