Mixed Gas Diving is an alternative to diving with compressed air. Thereby oxygen poisoning, which is imminent with compressed air cylinders at great depths, is not possible.

In order to enable deeper diving and to prevent a so-called rapture of the deep, there are gas mixtures. These are, as the name already says, a mixture of the oxygen necessary for breathing with other gases, which are comprised in our breathing air. So for example helium and hydrogen. In comparison to compressed air, these mixtures also have a minimum content of nitrogen.

So that the oxygen content is always balanced with the depth, the mixed gas process is mostly computer monitored.