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.

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, was hit with a Game Over.

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 before would happen: Link drowns and get Game Over unless possessing a fairy.

The oxygen gauge returns in Skyward Sword.