Standard O₂ Tank (Subnautica)

The tank is a crafted piece of equipment which boosts the player's oxygen supply by 30 seconds.

The player can carry multiple tanks at a time in their inventory to further increase their oxygen capacity (but lowering space for other things). The Tank takes up four slots (2x2) in the player's inventory.

By using the workbench the tank can be upgraded to High Capacity Tank or the lighter model, Plasteel Tank.

While each tank adds to the player's total amount of oxygen it also increases their weight, therefore decreasing the player's swimming speed.