When considering the use of Nitrox, why is it important to plan dives based on oxygen percentages?

Planning dives based on oxygen percentages is crucial primarily because it helps divers avoid oxygen toxicity, which can occur at higher partial pressures of oxygen. Enriched Air Nitrox contains a higher concentration of oxygen compared to regular air, and as divers descend, the partial pressure of oxygen increases. If the partial pressure exceeds safe limits, it can lead to central nervous system toxicity, which may result in symptoms ranging from visual disturbances to seizures, and in severe cases, it can be life-threatening.

When using Nitrox, divers need to calculate their maximum operating depth (MOD) based on the specific oxygen percentage they will be using. This ensures that during the dive, they will remain at depths where the partial pressure of oxygen remains within safe ranges. By planning dives according to the oxygen content, divers can prolong their bottom times safely while managing the risk of oxygen toxicity effectively.

The other options, while they may be relevant to diving in general, do not directly pertain to the specific risks associated with varying percentages of oxygen in Nitrox diving. For instance, temperature management and buoyancy control are important for overall diving safety and comfort but do not specifically relate to the dangers of partial pressures of oxygen. Equipment selection can be influenced by Nitrox usage, but it is not as