- "The weather in this area changes suddenly and violently, due to strong winds from the south. These stormy conditions cause ships to capsize, sending their crews to a watery grave; doomed to wander a maze of undersea caverns for all eternity."
- —In-game description.
Counting Ecclesia, Kalidus Channel is the fourth stage in the game. Ships sink regularly here due to violent weather caused by strong winds from the south. When the ships capsize, their crews are doomed to wander a maze of undersea caverns for all eternity. Shanoa goes through this level twice, once after completing Ruvas Forest, and again after defeating Brachyura in the Lighthouse.
Nearly the entire area is submerged in water, which is unnavigable without the Serpent Scale. The top part of the stage is the channel's surface, which is littered with floating debris from sunken ships. One can also find a large ghost ship rolling with the waves in the background. After obtaining the Serpent Scale, Shanoa gains access to the maze of undersea caverns that comprise most of the level. There's also a sunken ship at the bottom of this area that can be explored.
- Jacob can be found the first time Shanoa visits the level, near the first Save Point.
- Monica can be rescued on Shanoa's second visit to Kalidus, after obtaining the Serpent Scale. She can be found inside the rightmost room at the bottom of the sunken ship.