In Subnautica, enhancing your oxygen supply through tank upgrades is crucial for extended underwater exploration. Below is a comprehensive guide detailing the various oxygen tanks you can craft, their capabilities, and the materials required.

Oxygen Tank Upgrades

1. Standard O₂ Tank
– Max Oxygen Units: 75
– Blueprint Location: The blueprint is available by default when you start the game.
– Crafting Location: Fabricator
– Key Materials Needed:
– Fiber Mesh (made from Creepvine Samples)
– Titanium (obtained from limestone outcrops or scrap metal)

2. High Capacity O₂ Tank
– Max Oxygen Units: 135
– Blueprint Location: Found in data boxes located in the Twisty Bridges biome and various Alterra bases.
– Crafting Location: Fabricator
– Key Materials Needed:
– 1 Standard O₂ Tank
– 2 Glass (crafted from 2 Quartz each)
– 4 Titanium
– 1 Silver Ore (can be found in underwater biomes, particularly Argentite outcrops)

3. Ultra High Capacity O₂ Tank
– Max Oxygen Units: 225
– Blueprint Location: Unlocked by scanning a Sea Monkey Nest found in the Lilypads Crevice biome.
– Crafting Location: Modification Station (not crafted at Fabricator)
– Key Materials Needed:
– 1 High Capacity O₂ Tank
– 4 Lithium (found in various areas like Arctic Spires, Purple Vents, and Deep Twisty Bridges)

Upgrading Process

To effectively increase your oxygen capacity, you will follow these crafting steps:

– Crafting the Standard O₂ Tank: You begin with this tank, which serves as the base for further upgrades.
– Upgrading to the High Capacity O₂ Tank: Use the Fabricator to craft this tank once you gather the required materials.
– Upgrading to the Ultra High Capacity O₂ Tank: After obtaining the blueprint and required materials, use the Modification Station to create this ultimate tank.

Summary Table

| Tank Type | Max Oxygen Units | Blueprint Location | Crafting Location | Key Materials |
|———————–|——————|——————————–|———————|—————————————————-|
| Standard O₂ Tank | 75 | Default | Fabricator | Fiber Mesh, Titanium |
| High Capacity O₂ Tank | 135 | Twisty Bridges, Alterra bases | Fabricator | Standard O₂ Tank, Glass, Titanium, Silver Ore |
| Ultra High Capacity Tank | 225 | Sea Monkey Nest – Lilypads Crevice | Modification Station | High Capacity O₂ Tank, Lithium |

By following this guide and gathering the necessary blueprints and materials, you can significantly improve your diving duration in Subnautica, opening up new depths for exploration and adventure. Make sure to look in the specified locations to find blueprints and resources effectively! Happy diving!