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Tag Archive: inert gas


Originally posted 2019-02-22 12:34:35. Scuba Q and A: Why Do Deep Divers Use Helium? Q. Why is helium preferred over nitrogen for diluting oxygen during deep sea diving? Answer: There are three reasons why helium becomes a necessary addition to breathing gas as depth increases: Oxygen Toxicity Oxygen is known to cause central nervous system […]


Originally posted 2018-03-07 23:55:40. Nitrogen Narcosis – Perceptions of Susceptibility Examining the human factors influencing diver perceptions of susceptibility to nitrogen narcosis.  By Andy Davis Nitrogen narcosis is a hyperbaric neurological phenomenon. Its existence, symptoms and onset are known, even if medical science has not yet explained the physiological mechanisms causing it. Individual susceptibility to […]

Originally posted 2019-02-15 05:23:22. Gradient Factor Comparison Using A Simple 60m Trimix Dive Case-Study By Andy Davis. As a follow-up to my previous article, ‘A Logical Application of Gradient Factors Settings for Open-Circuit Tech Divers‘, I have decided to write a comparative case-study that illustrates the effect that three different gradient factor settings can have […]


Does Nitrogen Narcosis Impairment Persist? by Andy Davis. A new study on nitrogen narcosis challenges the long held presumption that nitrogen narcosis impairment dissipates immediately on ascent from depth.  A scientific study, ‘Persistence of Critical Flicker Fusion Frequency Impairment; Evidence of Prolonged Nitrogen Narcosis,’ first published in 2012 in the European Journal of Applied Physiology, by Costantino […]