[δείδω μή]
…τί μοι καὶ κῆτος ἐπισσεύῃ μέγα δαίμων
ἐξ ἁλός, οἷά τε πολλὰ τρέφει κλυτὸς Ἀμφιτρίτη:
[I’m afraid] that some god’s going to send a great sea-monster against me; glorious Amphitrite breeds them in numbers.
Odyssey 5.418-21
Culturally as well as geographically, the sea was central to the Classical world. These days we’re encouraged to think of the Mediterranean as something that united rather than divided the region, teeming with shipping and movement. All of this is true, but sea-faring was also deeply perilous,[1] especially in the autumn and winter. Shipwrecks and deaths at sea were common. It’s no surprise, then, that ancient Mediterranean waters were believed to be home to all manner of monstrous and deadly creatures.
Ancient Worlds 