One of the long-standing issues in the study of the French of England revolves around who exactly could speak, write, and read French in medieval England. Most scholars accept that few below the level of the aristocracy, upper gentry, and the clerical elite spoke French regularly, even in the heyday of French literary culture in England which stretched from the late twelfth to the late fourteenth century. We know too that lawyers and judges, most of gentry status but some from the upper bourgeois or even prosperous yeoman class, could read and speak French because it was the language of legal treatises and pleading in the royal courts. We are, moreover, starting to learn about the use of French in other social groups, as the essays in this volume by Marilyn Oliva (on nuns) and Richard Britnell (on townspeople) attest. My contribution follows on from this work in exploring non-elite, non-literary communities of French in medieval England by focusing on the use of French among sea-going populations, particularly mariners and fishermen, but also shipmen/merchants and other port-town residents who made their living from the sea. I look at three types of evidence: (1) the Laws (or Rolls) of Oléron, the dominant maritime law code of the medieval Atlantic world; (2) other types of port-town records, such as maritime courts, custumals, and customs accounts that were written in Anglo-French; and (3) indications that French may have been spoken or understood by many English overseas merchants and shipmasters and even a good number of mariners into the fifteenth century.