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This article is about the Ultra High Capacity Tank in Subnautica. Click here for information on this subject in Below Zero.
This article is about the Ultra High Capacity Tank. If this is not what you are looking for, see Oxygen Tank (Disambiguation).

The Ultra High Capacity Tank is a piece of equipment which is an upgrade to the High Capacity O₂ Tank. It can be crafted at the Modification Station after retrieving its blueprint from a Data Box. It boosts the player's Oxygen supply by 180 units, increasing it to a total of 225 O2.

The player must equip the Ultra High Capacity Tank in the tank slot of the Paperdoll UI in order to benefit from it. While not equipped, it takes up nine slots (3×3) in the inventory.

Note that when an O2 tank of any kind is built, it defaults to being empty: it must be equipped in an atmosphere in order to fill it. This is important if the player intends to carry multiple tanks for deep diving without a vehicle.


High Capacity O₂ Tank.pngLithium.png×4Arrow-right (1).pngModification Station.pngArrow-right (1).pngUltra High Capacity Tank.png



  • The Alterra logo is sported on the back of the Ultra High Capacity Tank.