What is the maximum recommended depth for EANx 36?

The maximum recommended depth for EANx 36 (Enriched Air Nitrox with a 36% oxygen content) is based on mitigating the risks of oxygen toxicity while balancing the need to avoid nitrogen narcosis.

At a depth of 30 meters (100 feet), the partial pressure of oxygen in EANx 36 is approximately 1.36 atmospheres. This level is generally considered safe for recreational diving, as it is below the commonly accepted limit of 1.4 atmospheres for oxygen exposure. Staying within this pressure minimizes the risks associated with high oxygen levels, such as central nervous system toxicity, while still allowing for a safe diving experience.

Diving deeper would increase the partial pressure of oxygen, which could lead to dangerous conditions. The other options suggest depths where the partial pressure of oxygen would exceed recommended safety guidelines, thereby increasing the risk of toxicity. This is why the 30-meter (100 feet) depth is viewed as the upper limit for safe EANx 36 diving based on current diving standards and practices.