In many long-enduring coastal cultures, there are stories – sometimes mythologized – about times when pieces of land became separated from mainlands by submergence, a process that created islands where none existed before. Using examples from northwest Europe and Australia, this paper argues that many such stories recall times, often millennia ago, when sea level in the aftermath of the Last Glaciation (last ice age) was rising and transforming coastal landscapes and their human uses in exactly the ways these stories describe. The possibility that these may have arisen from eyewitness accounts of these transformative processes, hitherto thought to be understandable only by scientific (palaeoenvironmental) reconstructions, should encourage more systematic investigations of such stories by scientists. It also suggests that science has traditionally underestimated the capacity of oral (pre-literate) cultures to acquire, encode and sustain their observations of memorable events with a high degree of replication fidelity.