Base Oxygen Overhaul

Base Oxygen Overhaul

What's This About?

So I got tired of how oxygen in bases is basically infinite and meaningless. You can build a sprawling 50-room complex at 500m depth and never think twice about where the air is coming from. That always felt weird to me.

This mod changes that. Now your bases actually need oxygen generators to stay breathable, and different rooms/modules consume different amounts based on their size. Build too big without enough generators? You're gonna have a bad time.

The Main Features

Air Synthesizer - This is the oxygen generator you'll be building. It's a compact unit that produces oxygen for your base. You'll need to place enough of them to keep up with your base's consumption, which scales with how many rooms and corridors you've built.

Atmospheric Processing Unit - A larger, more powerful generator that I'm still working on. Should be ready in a future update.

How It Works - Every base module has an oxygen consumption rate. Small corridors use less, big moonpools and multipurpose rooms use more. Your generators produce oxygen, and if production doesn't exceed consumption, you start losing oxygen while inside the base.

The nice thing is you can tweak everything in the mod options. Want generators to produce more oxygen so it's easier? Go for it. Want to make it brutal? Crank the production way down.

Base Snorkel - There's an option (disabled by default) that makes any base with at least one habitable section above water act as if it has infinite oxygen. Personally I leave this off but some people like having the option.

Visual Feedback - Generators have status displays that show ONLINE/OFFLINE/FLOODED. You can also hover over them to see your base's net oxygen production rate, which is super helpful for figuring out if you need to add more generators.

Why I Made This

Honestly? Base building in vanilla Subnautica feels a bit hollow once you have the resources. You just spam rooms without any real consequences. I wanted to add another layer of planning where you have to think about life support infrastructure, not just "does this look cool."

In early game, you'll be carefully planning your first few base pieces and prioritizing that first Air Synthesizer. Mid-game, expanding means deciding if you need more generators first or if you can risk building that non-pertinent observatory room. Late game, you're managing multiple generators across a sprawling deep-sea complex.

Difficulty Options

There's several toggles in the mod options:

[*]Partial Oxygen Loss - When enabled (default), oxygen loss scales with how negative your production is. When disabled, you lose oxygen at max rate regardless.