Why must divers plan their dives when using Nitrox?

Proper dive planning is essential when using Nitrox because it helps divers manage the risk of oxygen toxicity. Nitrox, which is a blend of nitrogen and oxygen, typically has a higher percentage of oxygen compared to regular air. While this can offer benefits such as reduced nitrogen absorption, it also means that the partial pressure of oxygen increases with depth.

Planning dives with Nitrox involves calculating the maximum operating depth for the specific blend being used to ensure that the partial pressure of oxygen does not exceed safe levels—generally 1.4 ATA for recreational dives. Beyond this limit, divers can experience symptoms of oxygen toxicity, which can lead to serious health risks including convulsions or other critical conditions while underwater.

By carefully planning dives, including paying attention to depth, time, and the specific gas blend used, divers can greatly reduce the risk of oxygen toxicity, enhancing their safety and enjoyment during the dive.