The Halogen Sea

Dividing the vast pillars of earth that form Faigan's continents is a stratified abyss of noxious gases spewing from the mantle. The Halogen Sea, referred to as such by only the loosest definition of a sea, is the planet's defining feature. It is as bountiful as it is deadly, and has been a place of great mystery since before the first mortals made planetfall, carried in scrimshawed arks.
Despite its name, the Halogen Sea contains untold myriad compounds, both gaseous and not, being synthesized and reacted with in volumes dictated by the tides, in seasonal occurrence. These compounds may exchange between strata as they transform, based on density, but for the most part remain at predictable depths.

The Chloric Layer

The largest layer, resting atop the others, the Chloric Layer is the most explored and understood level of the sea, accounting for nearly eight vertical kilometers. The first thousand meters alone contain roughly 99% of naval traffic, especially fishing blimps dangling nets to catch gasborne wildlife. As with any layer, pressurized protection and adequate air filtration is a must. The lower depths of the Chloric Layer are host to numerous refinement rigs; semi-permanent habitats that collect and amalgamate rare gases that settle in between layers.

The Bromic Layer

Lightless and subject to unbearable heat even by the standards of the residents on land, the Bromic Layer accounts for about three-and-a-half vertical kilometers. While bromine gas on its own is a valuable resource, the ecosystem is of greater interest, as it is home to extremely rare forms of life that bear little resemblance to anything encountered anywhere else in the Ravel. However, operations in this layer are made quite difficult by a number of factors; the 70-degree centigrade heat, new specimens frequently making themselves known by attacking platforms and submarines, and the frequent hydrochloric acid rainstorms that pound down from above. The submerged mountain ranges that rise into this layer are of great interest, as there is said to be evidence of civilization there, though these claims are heavily disputed.

The Iodic Layer

Comprising the deepest points of the ocean abyss, the Iodic Layer is slightly shallower than the Bromic Layer, except for its deep trenches, which may contain astatine compounds in greater quantitites than other planets. At these depths, it is too hot for water to exist outside the bodies of what scarce wildlife there is, many of which must ascend to hunt. Curiously, it seems that many creatures in this layer are chemoautotrophic, capable of synthesizing all necessary nutrition from proximity with deep ocean vents, and only hunt to satisfy a need for fluids. Very little is known about this layer, and its deepest discovered point, the Askigarna Rift, is the subject of equal parts curiosity and terror, not only due to its indeterminate depth, but also that even in the modern day, it cannot be said with total certainty that there are not other places just like it, if not even deeper.

Type

Ocean

Location under

Faigan

What about fluorine?

As reactive as it is, nearly all fluorine in the Halogen Sea has formed heavy compounds on the sea floor, coating it in bright colors scattered about by tidal force. Only trace amounts of gaseous fluorine remain, much of it in the clouds in the sky rather than the clouds in the sea.

Vapordrake Sightings

The most famous cryptid of Faigani fame, the vapordrake is a theoretical animal whose existence lacks confirmation, despite the number of sightings reported by the crew of defunct rigs in the Bromic Layer. Testimonies state that its wings are like blimps filled with combustible fumes, and that it expels them as flaming jets to convey its bloated body. In addition to its rumored phlegm net it uses in lieu of a breath weapon, it is said to maintain an entourage of minions, which it can eject along with this net at extremely high velocities to board vessels on its behalf. Beyond that, some have claimed it is sapient, capable of communication, and perhaps even psychic.