What this means in real life is if you are diving with NITROX 32%, you would simply never go deeper that 130 feet of water on that particular dive. This is an absolute rule that cannot be broken. But in reality, how often do you go that deep anyway ? And if you NEED to, then grab a cylinder of air. NITROX is actually limited to even shallower depths than air due to the increased oxygen content. The deepest you would want to use a standard NITROX mixture of 32% would be 130 FSW. Other mixtures, such as EAN 26 and EAN 28 can be used deeper, provided you are certified and trained and equipped to go to those depths.