The Deep Abyss

The Deep Abyss is our universe’s elemental plane of water. Many of the creatures there are grotesque and monstrous. Its denizens include the Bake-kujira, megalodon, the kraken, and all manner of aquatic monsters. Other residents include all manner of deep sea creatures. According to the lore of the Fortuna Archipelago, there are several portals -- or at least places where crossing over is easier than normal -- to the plane of the Deep Abyss in the Archipelago and surrounding waters, especially the deeper waters to the north.