Abyss, Submarines and Giant Corporations

Hardcore military + deep sea trek + abyssal syndrome + distant planet + AI ship girl Chen Du traveled to the deep-sea planet and worked around for ten years before buying a second-hand submarine with lots of patches. Creditors come to visit, pirates block the way, and even the fish on the bottom of the sea are more valuable than people. He thought he would rot in the four thousand meters of black water for the rest of his life. Until he picked up an old federal AI with silver hair and blue eyes. "I am the core of the Undertide ship. From today on, you are my captain." This broken ship has changed. He can dig mines that others cannot. He dared to enter the ruins that others dared not enter. What others see as a dead place, he serves as a channel. From a second-hand classic boat to a deep-sea fleet. From the broken captain of Krel Junction to the entire colony, no one dared to call him by his first name. But the deeper the sea, the greater the secrets. Things from the old days are waking up. Giant corporations, cults, pirates, and Cthulhu-like abyssal creatures emerge from the darkness one by one.