At the moment, it doesn’t seem like the environment along the southern map boundary has been fully explained yet, or perhaps that information is simply being withheld because it is work in progress. Of course, this could also be a misinterpretation on my part if i overlooked something. Either way, I’d like to share a personal design concept.
Southern map edge concept
Instead of using a uniform abyss and predator-based map boundary, the outer edges of the southern map could become part of the world’s environmental storytelling.
The southwest and eastern map edge could be a shallow hydrothermal reef system with acidic vents, extreme heat, corrosive water, and unstable sediment. This would naturally discourage exploration through escalating environmental hazards rather than relying immediately on a hard death zone, but after an escalation ( too shallow for a big sub, tot hot for the small one, and unstable ground for a mech suit bescause it get stuck in skudge) which keeps you out and you will die at last by the environment if you try to walk or swim trough it.
A natural breach in the reef near the southeastern power plant could explain the facility’s location. Strong upwelling currents pass through this channel from the south and southeast, creating a realistic barrier that pushes players back into the playable area while also providing a logical energy source for the power plant.
These currents could continue toward the northwestern deep-sea biomes and provide nutrient transport that helps explain also the existence of the tree organism in the northeast. And it could also help to explain why the breach functions as a hunting ground for predators, as migrating prey species might naturally be funneled through this passage by the currents.
The current breach (observatory and power plant) boundary could also be developed further as a dedicated Karakorum geoengineered zone, giving the area a more distinct identity and providing additional opportunities for environmental storytelling and worldbuilding and complements the power plant structure.
This approach would make the map boundaries feel like part of a connected geological and ecological system rather than simply the edge of the game world. And it would be more like the subnautica below zero approach.