When discussing "percent oxygen," what should divers be cautious about?

When discussing "percent oxygen," divers should be cautious about higher percentages because they correlate with increased risks of oxygen toxicity. Enriched air nitrox mixes contain higher levels of oxygen compared to regular air, which can pose a risk at certain depths and pressures. At these elevated levels, the partial pressure of oxygen increases, leading to potential neurological and pulmonary effects, which can occur if divers exceed specific limits based on their depth and the mix they are using.

Oxygen toxicity manifests in divers as symptoms like visual disturbances, ringing in the ears, twitching, and in severe cases, seizures or loss of consciousness. Therefore, educating divers about the safe limits for oxygen exposure at different depths and the signs of toxicity is critical for ensuring safety during dives with enriched air nitrox.

While the other options mention various aspects related to diving, they don't accurately address the critical safety consideration that arises with increased oxygen levels. Understanding and managing the risks associated with higher oxygen percentages is essential for safe diving practices.