Trimix Tools treats oxygen as a narcotic gas by default when calculating Equivalent Narcotic Depth (END) related results.
Treating oxygen as a narcotic gas is consistent with what many technical diver training agencies teach their students. There are also many divers and technical diving programs that prefer to consider only nitrogen as narcotic in their dive planning calculations.
The “Treat Oxygen as Narcotic” setting in the Settings tab gives you the option. Simply set this setting to “OFF” if you’d prefer that your END related calculations do not include Oxygen as narcotic. This setting is saved for subsequent invocations of the application so that you do not have to set it each time.
