Deinne

Deinne is the planet upon which all activity in Profundum Pontum takes place. Water covers more than 99% of the planet's surface; only a few hundred miniscule islands pepper the face of the otherwise endless cerulean mass.

The planet is home to numerous sentient races, the vast majority of whom reside largely or entirely underwater. Their more populous members have conceptually divided the world into three super-regions, based largely upon whether the majority of sentient species can live there.

The Lack
The Lack consists of the islands that protrude from the water across the world, as well as the sky. It is so named for the lack of water, lack of life, and lack of survivability that the aquatic world perceives there. Of all the sentient species in Deinne, only the Dryfolk live in the Lack long-term.

Once, a very, very long time ago, there was enough dry land for the Dryfolk to have a far larger, thriving civilization. It gave way to catastrophic experimental nuclear war, however, which ultimately left the entire atmosphere ignited in a reaction that caused radioactive isotopes to pollute the entire world's air, which continues to this day. Even those who are adapted to survive for short periods out of the water can be afflicted by the radiation, if they are not careful.

The High World
Most of Deinne's civilization exists in the High World. Those peoples who live there call themselves the High Races, though the Dryfolk are generally considered amongst this league as well. The High World generally consists of all parts of the world with a sea floor that does not drop much further than 1000 meters from the surface. Most of civilization tends to collect itself in cities in the higher ranges of these underwater elevations, but usually away from islands, except for the Dryfolk.

The High World is further divided into a number of continental shelves that more or less consistently stay above the 1000 meter mark. They often serve to split apart Nereidian cultures and countries, as both travel and communication between shelves is rare, time-consuming, dangerous, and unreliable for most.

The Deeps
The remainder of the planet -- that 62% majority of the ocean that extends below the 1000 meter mark -- is known collectively as the Deeps. Though most aquatic civilizations can technically survive in the upper reaches of the Deeps, they are generally considered inhospitable and extraordinarily treacherous. As the sea floor falls below the furthest reaches of sunlight, travelers lack fixed landmarks by which to navigate. Small sea life, which many aquatic civilians depend upon for food, dwindles to almost nothing. In its place, far larger creatures prowl. Some of them are tremendously dangerous and predatory. Others are simply far too large for most folk to even attempt to hunt.

Below the depth of 1000 meters, most High Races cannot survive the crushing pressure without some manner of special protection, be it from Aura, Dryfolk technology, or something else. They must bring their own source of light, as almost no natural iight is found below. The tales that have been spun by the few who were brave and lucky enough to venture well into the depths of the Deeps and return were filled with the sorts of things that inspire the wildest of dreams in children, both wonderful and terrible. There are tales of ruins of civilizations unknown, and some bizarre peoples who still persist in the shadows of the world. There are stories of fabulous treasure and powerful magical artifacts that defy the limitations of Aura. There are legends of wicked curses, forbidden reaches, and monolithic monsters so ridiculous in power and mass that no force known to Deinne could bring it down, or sate its hunger. All of these fanciful myths, and the High Races have hardly explored the tiniest fraction of it.