Twin Ocean, a unique sea area located among the Southern Islands south of the continent.
Just like its "twin" name implied, the seawater in this region resembled a pair of twin siblings—different in color, yet existing side by side with a clear distinction between them.
One side was crystal clear and transparent, reflecting the azure sky, while the other displayed a rusty, clay-like reddish brown.
The two colors of seawater did not mix. There was not even a transitional zone where their colors blended; instead, they were divided into two distinct sections by a tangible boundary, as clearly separated as "oil" and "water."
Viewed from high above, it looked as though some invisible force had forcibly stitched two entirely different sea areas together. It was strange and remarkable.
No one knew why such a natural phenomenon had come into being. Ever since the first adventurer from Barracuda Bay set foot here, this sea area had already looked like this.
People had asked the islanders who had lived in the surrounding waters for generations about it, but their accounts varied.
Some said it was a trace left behind when the Ocean Goddess Umberlee and the Sailor God Valkur battled in ancient times. Others said that a powerful monster from the deepest reaches of the heavens was buried beneath the seabed here, and the blood flowing from its wounds had dyed the nearby waters red.
Over the years, many geologists and oceanographers had hired adventurer fleets to conduct on-site investigations. They concluded that the reddish-brown sea area had formed because of the red clay and unusual iron-rich rock layers beneath it.
However, no one had offered a credible explanation for why the two entirely different colors of seawater could remain so distinctly separated. In the end, it could only be explained as