In the ancient Mediterranean world, the sea was an essential domain for trade, cultural exchange, communication, exploration, and colonisation. In tandem with the lived reality of this maritime space, a parallel experience of the sea emerged in narrative representations from ancient Greece and Rome, of the sea as a cultural imaginary. This imaginary seems often to oscillate between two extremes: the utopian and the catastrophic; such representations can be found in narratives from ancient history, philosophy, society, and literature, as well as in their post-classical receptions. Utopia can be found in some imaginary island paradise far away and across the distant sea; the sea can hold an unknown, mysterious, divine wealth below its surface; and the sea itself as a powerful watery body can hold a liberating potential. The utopian quality of the sea and seafaring can become a powerful metaphor for articulating political notions of the ideal state or for expressing an individual’s sense of hope and subjectivity. Yet the catastrophic sea balances any perfective imaginings: the sea threatens coastal inhabitants with floods, tsunamis, and earthquakes and sailors with storms and the accompanying monsters. From symbolic perspectives, the catastrophic sea represents violence, instability, the savage, and even cosmological chaos. The twelve papers in this volume explore the themes of utopia and catastrophe in the liminal environment of the sea, through the lens of history, philosophy, literature and classical reception. Contributors: Manuel Álvarez-Martí-Aguilar, Vilius Bartninkas, Aaron L. Beek, Ross Clare, Gabriele Cornelli, Isaia Crosson, Ryan Denson, Rhiannon Easterbrook, Emilia Mataix Ferrándiz, Georgia L. Irby, Simona Martorana, Guy Middleton, Hamish Williams.