At the Eye of the Ocean's core, ancient submarines covered in rust and moss lay beneath the waters, some reduced to mere metal scrap with interiors filled with water.
Yet, some of these submarines are still operational, which is abnormal.
If you are a planet civilization, and if this civilization happens to be on a planet mainly composed of the ocean.
When the technology tree reaches a certain level, a choice inevitably appears: outward or inward.
Outward means exploring outer space.
Inward, however, divides into two paths: one being the excavation of the planet to establish an underground world, and the other is entering the ocean, which covers over 50% of the surface.
Depending on which technology branch you illuminate, your choice naturally varies.
High-tech materials that resist water and pressure, and advanced energy materials that absorb high temperatures from the Earth's core, whichever is discovered first, will be used first.
