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 to further increase their oxygen capacity (but lowering space for other things). The Tank also take up four slots in the player's inventory.

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

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