has there ever been a case study that concluded it was in fact safer? IOW a lower incidence of DCS?
My training said the answer was no. Is that no longer true?
Sure, it doesn't hurt... but can you prove it helps? My training 12 years ago said the answer was no. Has this changed?
Can I ask what training stated that?
There are several agencies that heavily promote, or even stipulate, the use of nitrox over air (in training).
Less nitrogen uptake has a direct impact on DCS risk mitigation. There are obviously other issues that can raise risk, such as; pre-disposing factors (dehydration/fatigue/obesity/cold/ exertion etc) as well as dive-related issues like fast ascents or insufficient decompression. However, in all cases a lower absorbed amount of nitrogen corresponds directly to the relative DCS risk in any given scenario.
Consider nitrox use from the perspective of EAD (equivalent air depth). Would you say that a dive of
X duration at 30
ft presented less DCS risk than a dive at
47ft depth?
In some (all?) training materials, agencies are quick to specify that "
nitrox isn't safer", but that is because it balances lower DCS risk against the risk of oxygen toxicity. Quite simply, from a safety perspective there are pros and cons to nitrox use. They are
not saying, however, that "
nitrox isn't safer from a DCS perspective"... that would be a wrong interpretation of the training.