Oxygen Gauge

An oxygen gauge is a gauge that appears whenever Link is underwater without a method allowing him to breathe underwater. Oxygen gauges have taken on multiple forms in the series. Thus far, they have only appeared in 3D main console titles.

The first type of oxygen gauge appeared in Ocarina of Time and Majora's Mask as a timer appearing below the Magic Meter counting down until Link's remaining air supply expired. Once the timer runs out, Link drowns and, unless in possession of a fairy, is hit with a Game Over. Link can spend an unlimited time underwater if equipped with the Zora Tunic (in Ocarina of Time) or if in Zora form (in Majora's Mask).

Twilight Princess introduced the first actual graphical gauge to count down Link's air supply, here appearing where preceding 3D games would put their Magic Meter. The more time Link spends underwater, the shorter the brighter part of the gauge gets, and once the gauge becomes fully dark, the same result as in previous games occurs: Link drowns and gets a Game Over unless he possesses a fairy. Much like the Zora Tunic in Ocarina of Time, the Zora Armor grants Link the ability to remain underwater indefinitely without drowning.

The oxygen gauge returns in Skyward Sword, taking the form of a circular meter similar to the Stamina Meter. Using the spinning charge move underwater causes the gauge to deplete faster during the move's execution. Touching a poison gas bubble also depletes a large section of the gauge at a time. Unlike its appearances in previous games, when the gauge is fully depleted Link does not die instantly but instead begins to lose health. He continues to lose health until he dies from his health being reduced to zero or reaches an air source such as the water's surface or an air bubble. The use of an Air Potion affects how the gauge from depleting for three minutes; the basic Air Potion reduces the rate the Oxygen Gauge depletes, while the Air Potion + prevents the Oxygen Gauge depleting entirely.