A Gathering Storm
The Shadowfell: The Shadowfell is the land of the dead, and is best shunned by the living; despite this, some have pierced the veil of death and returned to tell of it. The stories of these people paint the shadowfell as a grim place: no land breaks the endless grey waters, no wind or wave ever ripples the surface. The only things to be seen aside from water are creaking barges that drift across the sea, crewed by hooded figures, carrying unknown cargo to some distant, unseen port.
The Abyss: The Abyss is an immpossibly deep sea filled with tumourous coral, demonic leviathans, and poisonous algae. Floating through these waters are ghost ships crewed by the damned souls of traitors, pirates, and deserters. At the murkiest depths of the Abyss lie sunken cities inhabited by aquatic demons, servants of inconceivably ancient masters.
The Feywild: Occasionaly, a mortal catches a glimpse of the realm of the fey: a traveler visits an island but it is gone when he tries to return; sirens lure a wayward vessel from one world to the next; a ship is led through the mist by music from an unseen fiddler. But these interactions with the Feywild are fleeting, the fey don’t like to involve themselves in the affairs of mortals very often.
The islands of the Feywild are as isolated from each other as they are from the mortal world; the fey don’t travel aboard ships, so those who can’t breathe underwater are stuck forever on the island on which they were born.