Theme: Deep ocean horror, leviathans, fear
Geography: Black water, abyssal trenches, cold currents
Culture: Fishermen who refuse to speak of the deep
Dangers: Maw Serpent pulses, hollow currents, bonewhale pods
Factions: Deepwatch Priests, trench hunters
Trade: Deepwater pearls, abyssal fish, rare minerals
Magic: Psychic resonance, trench magic
Adventure Hooks:
A trench expedition goes missing
The Maw Serpent stirs, causing fear pulses
A cult tries to awaken something ancient