Ultra High Capacity Tank (Subnautica)

The High Capacity Tank is a piece of Equipment and an upgrade to the regular O2 Tank. It is crafted by using the Modification Station.

It boosts the player's Oxygen supply by 120 seconds. This is twice as much as a regular tank.

The player can carry multiple tanks at a time however only the tank equipped to the Paperdoll UI will affect oxygen levels. The High Capacity Tank also takes up four slots in the player's Inventory.

(As of update B55, the High Capacity Tank does not affect player speed.)