What is a significant disadvantage of only using air tables when planning Nitrox dives?

Using only air tables when planning Nitrox dives can lead to underestimating your oxygen exposure, which is a significant disadvantage. Nitrox contains a higher percentage of oxygen than regular air, which alters the way tissue absorbs both oxygen and nitrogen. Air tables are designed for dives using regular air as a gas mixture and do not factor in the different absorption rates of oxygen present in Nitrox.

When divers use air tables, they may inaccurately assume that their nitrogen exposure is the only concern, neglecting the potential risks of oxygen toxicity associated with deeper dives or longer exposure times while using Nitrox. This oversight can lead to situations where divers unwittingly exceed safe levels of oxygen exposure, increasing the risk of oxygen toxicity or other related health issues.

Thus, relying solely on air tables does not provide the necessary data for safe dive planning when using Nitrox, making it crucial for divers to utilize specific Nitrox tables or dive computers that account for both nitrogen and oxygen exposure.