The area is geologically and geographically typical for an abyss, with a seafloor adorned with volcanic chimneys and caverns carved into the cliff walls. However, the inherent darkness that comes with being so far away from the sun can lend the player a sense of apprehension if they don't know what lurks in the shadows around them.
The South Crevasse is inhabited by splendid alfonsinos, a couple of Giant Siphonophores and an aggressive Bluntnose Sixgill Shark that will attack the player on sight. A megamouth shark also patrols this area.
At a depth of around 400 feet (122 meters), the player can find this small cave embedded into the wall. Vampire Squid patrol this cavern, waving the glowing tips of their tentacles to confuse enemies. This cave is the resting place of the Terra Coin.
These caverns next to each other in the wall of the Southern Crevasse are near the ocean floor. A bluntnose sixgill shark guards the entrances to the caves, often surprising players with its stealthy approach from the darkness.
In one of the caves, the player will find a group of Giant Isopods, large crustaceans resembling pill-bugs, and in the other a group of Vampire Squid. However, the latter cave will also eventually become home to a particularly unique isopod that the player must discover with Oceana's help.
The Chimney Forest is, as its name suggests, a large conglomeration of hydrothermal vents adorning the seafloor. Unlike the vents in the first Endless Ocean game, these vents are not active and do not become active over the course of the game.
The North Crevasse is quite different from its counterpart in many aspects. With a seafloor bare of chimneys, this canyon is home to the single Giant Squid in this game (not counting the oxymoronic smaller giant squid in the Cavern of the Gods), as well as other distinctive forms of life, like the sea pigs that patrol the ocean floor. This Crevasse is also home to an Oarfish, as well as a pod of Risso's Dolphins that live closer to the seafloor.
Though the North Crevasse has many differences from its twin, they both are home to a small, dead-end cave. This cavern is located at a depth of around 300 feet (91 meters) and is inhabited by a shoal of popeye grenadiers. A Megamouth Shark patrols the nearby area, and is not aggressive.
Matthias Louvier, the son of Jean-Eric Louvier, piloted a submarine named the HD-9. The wreckage of that submarine can be found here in the Courtyard, suggesting that Mathias died attempting to explore the depths in pursuit of the Song of Dragons. Investigating the submarine will grant the player Matthias's last letter to his father, as well as the final piece of the Dragon Flute.
In the zoom-mode glows located around this area, the player can find Firefly Squid (primarily in the Giant's Lair) and Giant Sea Spiders, as well as the occasional Humpback Anglerfish. This area is also where the player can find the Microscopium Coin.