Increased oxygen partial pressure typically has what effect on allowable dive time?

Increased oxygen partial pressure shortens allowable dive time due to the increased risk of oxygen toxicity. When you dive deeper or use a mix with a higher percentage of oxygen, the partial pressure of oxygen in your breathing gas increases. This elevated partial pressure can lead to central nervous system toxicity, which manifests as symptoms such as visual disturbances, muscle twitching, or seizures.

To mitigate this risk, divers must adhere to exposure limits for oxygen, which dictate maximum allowable dive times at various depths when using enriched air. The greater the partial pressure of oxygen you are exposed to, the shorter your safe dive time becomes, necessitating careful monitoring and adherence to established dive tables or computers that factor in these limits.

Understanding the implications of oxygen partial pressure is crucial for maintaining safety during dives, especially when utilizing enriched air for longer dive profiles.