External auditory exostoses (EAEs) are osseous exostoses that form in the external auditory canal as a result of an irritation of the periosteum. Many conditions can be responsible for this irritation, but contact with cold water is the principal cause. This article is a brief review of clinical and anthropological studies that permit consideration of EAEs as faithful markers of water-related activities in past populations and discusses the potential as well as the limits of EAEs to provide insights into aquatic resource exploitation by prehistoric humans.