Gu Fan continued to ponder, and the longer he contemplated, the more anxious Lisa grew.
"If this island is a secret base, then sinking it in the sea would make it hard for people to discover. Keeping it mobile would make it even harder to find. When it emerges, using fog for camouflage is intended to prevent anyone from finding it. Choosing to surface on gloomy nights matches the conditions under which fog occurs, making it seem reasonable. But what's strange is that if it's a secret base, why does it need to surface? To breathe fresh air? I don't believe that the ancient Super Civilization lacked an air circulation purification system," Gu Fan said, all the while gazing at Lisa, whose expression became increasingly unnatural.
Su Hui caught on, "So Gu Fan, you mean, the island doesn't need to float above the sea surface, it can remain submerged. But for convenience, Lisa manipulates it to surface under gloomy conditions and release the fog."