Oxygen is an Attribute or Character Stat in MMO Atlas.
The value of your Oxygen Attribute in MMO Atlas denotes how long you may remain underwater without beginning to drown, as well as how fast you move in the water.
Fully submerging in water will cause you to drain Oxygen over time until you either surface, at which point the Oxygen stat will regenerate until you re-submerge, or begin to Suffocate when your Oxygen reaches 0. Once you are suffocating, your Health will begin to drain rapidly until you either surface, or die.
Increasing Your Oxygen Attribute
Putting one skill point into Oxygen will increase your maximum Oxygen by 10.