The shining Aetherium saltwaters of the Endless Sea are a nexus for lost seafarers, washed away in storms, trapped in long calms, and turned around by thick fogs.
Finding oneself in the endless sea is the easy part of course. No one is known to leave the waters, at least alive.
The islands of the Endless Sea shift continuously, making mapping difficult, but some permanent settlements, known as Burh, appear from time to time.
The oldest of these island settlements are known as the Elder Isles, though only a few of them continue to exist. Hybrasil, Roccabarraigh, Long Sault, all now lost, while Ys and Aiaea somehow remain.
The younger Burh – Iram of the Pillars, Nan Madol, Ravenser Odd, Kitezh, Sri Vijaya, Yonaguni, Reimerswaal, Cagway, the floating Baochuan – are home to many different races from many different worlds and traditions, though commonality and difference come in equal measure.
The centre of the Endless Sea never changes, and all compasses point to the mysterious monolithic dark tower that rises from the deeps and disappears into the sky. Known simply as the Oud, it is presumed to be a remnant of the disappeared Vinatan civilisation, whose relics sometimes appear on various islands or wash up from the depths.
The Endless Sea is a swashbuckling, sword and sorcery setting for Dungeons and Dragons 5e, using optional rules for flintlock firearms.
Players take on the role of exiles from various worlds, or those born on the Sea to those exiles. Humans, Genasi, Tieflings, Kenku, Changlings, Shifters, Tabaxi, Gnomes, Goblins, Triton and Kobolds all find their ways to the Sea, bringing with them magic and technology not known to the other races. Most seem to come from their own worlds, though the origins of the Changelings and Triton are so lost to time that they have been forgotten.