Epithets: Bythios
Abyssal, of the deep, of the Sea, Abysmal.
O nether one, goddess of depths, eternal, Goddess of dark, come to my sacrifices. Fulfil for me this task, and as I pray Give heed to me, Lady, I ask of you. - PGM IV 2441-2621, detail lines 2564-2567.
Hekate has numerous epithets that relate her to both the Underworld and the Sea. From Her earliest days, Hesiod describes her as a Goddess that spans both, as well as having her share of Heaven. In the Homeric Hymn to Demeter, Hekate is in a cave when she hears Persephone’s abduction.
Bythios isn’t widely used, nor explored by scholars. So I haven’t had much luck finding academic insights here.
We should not be surprised to find this epithet from the late antique period, nor that the PGM would be the source, where we see long strings of epithets dedicated to a range of Gods.
Historically, she is also:
Aidonaea, of the Underworld Anassa Eneroi, Queen of the Dead Chthonia, of the Earth Einalia, of the Sea Epigeia, of the Earth Katachthonia, Subterranean Limenitikos, of the Harbor Limenoskopos, Watching the Harbor Nerterios, Infernal Nerteron Prytanin, Mistress of the Dead Rexichthon, Earth-Cleaver, an epithet that calls Poseidon to mind Tartaroukhos, Ruler of Tartaros Tymbidian, Sepulchral
Clearly, the idea of Hekate being associated with the depths of both the Earth and the Sea are well founded. It would be a good experiment to reach out to Hekate Bythios in a cave and then on the sea shore and take note of how well each proceeds. If you do it, feel free to message me! (I have neither caves nor seashore near me.)
Sources:
Lsj.translatum.gr Hekate’s Many Names: http://nehetisingsforhekate.tumblr.com/post/87604951156/hekates-many-names-part-1-of-3
Betz, Hans Dieter. The Greek Magical Papyri in Translation: including the Demotic Spells, Chicago, 1992. Cook, Erwin. The Homeric Hymns, Trans. Athanassakis, Johns Hopkins, 2013. Eidinow, Esther and Julia Kindt, eds. The Oxford Handbook of Ancient Greek Religion, Oxford, 2015. Hesiod. Theogony, Works and Days, Shield. Trans. Athanassakis, Johns Hopkins, 2004.
Images:
Alfie. “Cave in Kardamyli, Messinia, Greece,” photo, 2006. Via wikicommons: https://commons.wikimedia.org/wiki/File:Katafygi_Vatsinidi.jpg