If you near an oxygen limit while diving, what should you do?

When you approach the oxygen limit while diving, ascending is the correct action to take. This is because the partial pressure of oxygen increases at greater depths, which can lead to oxygen toxicity, a serious and potentially life-threatening condition. By ascending, you reduce the partial pressure of oxygen and mitigate the risk of experiencing harmful effects.

Diving deeper can increase the likelihood of reaching or exceeding the oxygen limits, putting you at greater risk. Staying at the current depth may not address the issue of nearing the limit, as it keeps you exposed to potentially harmful levels of oxygen for an extended period. Signaling for help without changing depth does not resolve the immediate risk and may limit your ability to respond effectively to the situation.

In summary, ascending to a safer depth where the oxygen exposure falls within acceptable limits is crucial for maintaining safety and avoiding complications related to oxygen toxicity.