High Capacity O₂ Tank (Subnautica)

The High Capacity O₂ Tank is an upgrade to the Standard O₂ Tank that is crafted at the Fabricator, being the only upgrade not requiring Modification Station. It can only be crafted after the player has acquired a Standard O₂ Tank. While equipped, it boosts the player's maximum Oxygen supply by 90 units.

The player must equip the High Capacity O2 Tank in the tank slot of the Paperdoll UI in order to benefit from it. While not equipped, it takes six slots (2x3) in the inventory.

It can be upgraded into the Lightweight High Capacity Tank or the Ultra High Capacity Tank at the Modification Station.