Will Argon Keep a Drysuit Diver Warmer?

Some divers, particularly technical divers, go to the trouble of carrying a tank of argon for drysuit inflation because they believe that argon makes them feel warmer in comparison to air. But Simon Mitchell, a dive physiology expert and past vice president of the Undersea and Hyperbaric Medicine Society, says this assertion hasn’t been proven. “There is a vast potential for a ‘placebo effect,’ where parameters like perceived warmth are being subjectively judged,” he recently wrote in Dive New Zealand. “Put another way, if a diver is told that a particular dry suit inflation gas will make them feel warmer, there is potential for the ‘power of suggestion’ to influence their judgment.”

He cited a 2001 study published in the journal Undersea and Hyperbaric Medicine, in which the authors ran dives without telling the divers what drysuit inflation gas was being used. The authors placed electronic temperaturemeasuring probes on the divers to accurately measure temperatures. There was no difference in the magnitude of the temperature drop between the dives with argon or air as the drysuit inflation gas. Nor was there any difference in divers’ opinion of their warmth. Mitchell says if there is a warming benefit, it is unlikely to be substantial.

P.S.: The same conclusions can be made for anecdotes about how breathing Nitrox keeps divers warmer underwater. Dive experts say there’s no scientific evidence to show that it’s true.