The Atlantian Base And Operation.

At a certain part of the sea, inside the cliff surrounding the ocean volcano was another influence of Atlantians after so many years.

The Crimson fleet under Staff Sergeant Barnes' command already created their base of operations in the cliff. They imitated the sea creatures in this region, annihilating a family of predators that once occupied a cave in the cliff.

After annihilating the predators, they took the cave for themselves.

Some of Barnes' advisors suggested that their base should be made inside the 17 warships and not inside a cave originally inhabited by dirty predators, granting them more maneuverability but the Staff Sergeant refused. 

Making their base of operations inside the warships was not impossible, but the Staff Sergeant still refused.