A turbulent family
ther than the vast-and-encompassing Aequin Ocean, Sister Seia is the most prominent body of water known to casterways. It is also known as the Violet Seia due to it's distinctly purple hue that is most evident during dawn or dusk when gazing over a large expanse of the water.
Beyond the Sea
At the dawn of casterway civilization, it was not known if there was anything beyond the Sister Seia. Prevailing winds meant that it was far-too-easy for a careless sailor to end up blown so far off course that they would end up on an unwitting journey to Islegantuan. But returning back to the comforting confines of Auld Cervia was an entirely different matter. It wasn't until 343 AoC that anyone who had been blown across the salty expanse managed to keep their ship intact and actually sail back to Islemanoton to tell the tale. It was only from that point forward that the Auld Cervians truly understood that there was another massive land area beyond the Sister Seia.
The sea gets its name from the Sisters. They are a unique trio of tiny moons that orbit Excilior geosynchronously. Specifically, the three multi-colored satellites (that usually appear to the naked eye as brilliant stars) always hover over the exact same spot, roughly in the middle of the Sister Seia. This incredible phenomenon provides a critical navigational aid for all who are trying to chart their course over land or sea.
he sea separates the continents of Islemanoton and Islegantuan to the east, and Isleprimoton to the west. At its narrowest point between the western edge of Tumia and the southeastern tip of Torholmaa, it is nearly 1,200 kilometers across. It is bordered on the north and south by the Aequin Ocean. A sea journey across the Sister Seia, from northern edge of Poglia to the southern extent of Torholmaa would be nearly 3,200 kilometers. Due to the assumed-global extent of the Aequin Ocean, it would be theoretically possible to sail north, out of the Sister Seia, past Poglia and the equator, and eventually circumnavigate all the way around to the southern edge of Sister Seia. However, there has never been a creditable account of such a journey ever being completed. For that matter, there is no such journey - other than those found in heroic fables - that has ever even attempted such a feat.
The sea is notorious for violent storms, arising seemingly from nowhere, that are easily capable of swamping entire fleets. Adding to this treachery is the preponderance of massive leviatons. These epic beasts can sometimes be seen battling each other - and such conflagrations are known to have ruined many fine ships as collateral damage. But even when they are not hunting one another, they are known to aggressively attack ships of all kinds. For these reasons, courses charted directly across the sea's open waters are avoided whenever possible. For example, shipments embarking from the ports of western Islemanoton, due for the eastern ports of Isleprimoton, will usually travel north, hugging the coast, skipping across from Egress Island to Smugglers' Moot, skimming the shores of Thigry Island, then dashing across the mouth of Leviaton Sound before eventually making their way to the trading centers of God, Igne, Nilaslia, and Torholmaa. Of course, such tactics are exceedingly slow and significantly more expensive. So the desire to avoid catastrophic loss must also be balanced against the value of the ship's cargo and its mission. This circuitous route, while much safer, is also highly impractical for trade that takes place between the southwestern nations of Islegantuan and the southeastern nations of the Sontsu Peninsula. Therefore, there is a common shipping route that sees heavy traffic between the port cities of Bagnano in Cervi and Kauhaloge in Torholmaa - but this route is one of the most dangerous in the world. Over most of its surface, the prevailing winds are westerly or southwesterly. This makes the journey to Islegantuan faster and easier. During certain periods in the spring and fall, these winds can be so consistent as to make eastward journeys over the sea nearly impossible.
Fauna & Flora
ike its parent, the Aequin Ocean, Sister Seia is stalked by an array of aggressive leviatons. Those creatures are not of a single species. In fact, some forms have only been witnessed once. So there is no reliable way to catalog and classify all of the giant species that may, at any given point, be lurking below the waves. This task is made even more difficult by the fact that razers, leviaton attacks, and (ultimately) shipwrecks are all closely associated in an intricate web of cause-and-effect. This means that any real impacts that are suffered from leviatons becomes inextricably intertwined with legend. Of course, there are billions of metric tons of biomass in the Sister Seia that have nothing to do with leviatons. The sea supports a splendorous menagerie of fish, plants, corals, and all manner of aquatic creatures. Most of those species are known, but there are still times when an exotic and alien-looking beast is caught in a fisherman's net, or washes up on shore.