What is the highest percentage of oxygen that can be used at a planned dive depth known as?

The term that describes the highest percentage of oxygen that can be used at a planned dive depth is known as the "best mix." This concept revolves around optimizing the gas mixture for specific dive conditions in order to maximize safety and reduce the risk of oxygen toxicity as well as other complications related to high-pressure environments.

When planning a dive, divers must consider factors like the depth of the dive, the duration, and the physiological effects of increased partial pressures of gases, particularly oxygen. The best mix is tailored to balance these considerations effectively, ensuring that divers can take advantage of the benefits of enriched air nitrox while still adhering to the safety limits imposed by the depth of their dive.

Other terms like maximum mix, safe mix, or standard mix do not specifically refer to this optimization of gas mixtures in the context of ensuring the highest level of safety and efficiency for a dive. Understanding how to choose and use the best mix is crucial for Nitrox divers to enhance their diving experience while minimizing risks.