How should divers monitor their air supply during a dive?

Monitoring air supply is critical for divers to ensure safety and avoid running out of air while underwater. Utilizing dive computers or pressure gauges provides real-time information about the remaining air in a diver's tank. Dive computers track air consumption patterns over the duration of the dive and can often provide alerts for needed ascents or safety stops based on air supply and depth. Pressure gauges visually indicate the remaining air pressure within the tank, allowing divers to make informed decisions about when to begin their ascent based on their remaining air supply.

In contrast, relying on guessing based on experience does not provide a reliable measure of actual air supply. Monitoring air solely during ascent can lead to dangerous situations if divers do not have sufficient air for safe decompression. Counting breaths may give a rough estimate of air consumption but does not provide an accurate representation of the remaining air supply in the tank, which is influenced by varying factors like depth and dive activity. Therefore, using dive computers or pressure gauges is the most effective and safest approach for monitoring air supply.