What is a key safety consideration when using mixed gases for diving?

Regular monitoring of gas mixtures is essential when using mixed gases for diving because it ensures that divers are correctly managing their exposure to varying oxygen levels and potential narcotic effects of other gases. Diving with enriched air nitrox, for instance, involves the risk of oxygen toxicity, especially at greater depths. Monitoring gas mixtures allows divers to confirm that they are using the correct blend for their planned dive, as even small deviations in gas mixture can significantly affect the dive's safety and outcome.

Ensuring that the gas mixture aligns with the planned depths and dive profile is critical to avoid decompression sickness and other diving-related illnesses. It is also important to regularly check gas pressures during the dive to ensure that divers have sufficient gas for their ascent and safety stops.

Other options, such as using larger tanks, allowing longer ascent times, or using multiple dive computers, do not address the immediate key safety consideration of having the correct gas mix while underwater. Regular monitoring is a proactive step that directly impacts a diver's safety and health during the dive.