Geography
Shaethon is assumed to be a much larger plane than the Material Plane, although it has not yet been fully explored. The plane boasts very few land masses and is estimated to be approximately 98% ocean. However, this ocean is relatively shallow across a large portion of the plane but contains a complex topology with deep chasms as well as several underwater volcanos. According to the local inhabitants, approximately half of the world is contained in a wide, unimaginably deep chasm known simply as
The Blue. This area is sparse of large-bodied life, especially in deeper regions, and is generally avoided by the sentients of the plane.
Small islands, usually less than than 4,000 square miles in size, dot the shallow side of the Shaethon known as
Krian'al, roughly translating to 'Life Waters' from the native tongue. These islands may host some primitive forms of terrestrial flora but are usually devoid of creatures. If settlements exist on these volcanic islands, they are usually positioned well underwater, along the ridge of the volcano. The waters of Krian'al do not generally exceed 4,000 feet in depth. Due to the brightness of Sheathon's twin suns,
Canthal and Pinayor Sol, strong sunlight provides ample energy for the development of life in Krian'al even at its maximum depth.
History
The sentient inhabitants of Shaethon, called
Mer or 'Water Genies', have been present on the plane at least since its discovery by sentients of Fearun. Mer are generally humanoid in form, although they are covered in tiny scales and have webbing between their digits and extremities. It is thought that the mer learned to control the water around them from water elementals that roam the plane.
The mer have traditionally been a people of war and conflict, raising and destroying cities repeatedly across Krian'al for as long as history remembers. Because of this, much of history is passed verbally and solid documentation of historical events is difficult to come by.
Mention of one event seems to arise in many of the mer tribes which references the near-death of the plane. Although details are difficult to resolve, it can be assumed that Shaetheon suffered a mass extinction hundreds of thousands of years ago which nearly wiped out the mer. This was likely caused by a celestial event which positioned the plane too close to its twin suns for a brief period and scorched much of the life around Krian'al. According to legend, only a small body of mer survived by receding into The Blue during the event. Clearly, the mer were able to re-establish themselves in Krian'al after Sheatheon had moved from its perilous position. However, it is said that some stayed behind and remain as an established population of deep-sea mer.
Connection to Faerun
The mer have made contact with the sentients of the Material Plane intermittently, though never for very long. Connection is thought to be through the use of a single, relatively stable portal between the two worlds. In Shaethon, this portal is located approximately 3,000 miles into The Blue. In Faerun, it is connected at the
Everswirl of Alaron in the Sword Sea.
This portal seems to have been relatively stable for the majority of known Faerunian history. Although passage is usually possible from Shaetheon to Faerun, the reverse is almost never true. Historically, successful passage from Fearun to Sheatheon has only been documented a handful of times, and has always been executed with the aid of visiting mer. On an unsuccessful attempt, the ship used for passage is either completely destroyed or ejected out of the Everswirl.
The reason for mer visiting Faerun is unclear. Without any true form of world government, the mer seem generally uninterested in alliances or conflicts. It is thought that when they do appear on the Material Plane, mer do so only so for the purposes of curiosity and exploration-- although some fear that they come only to spy for Shaeth, who is bound to their plane. In some cases, mer may successfully procreate with a human to produce a water genasi, and pass some of their elemental power to these children.
