What is the first recommendation if the oxygen supply is lost while a diver is submerged?

In the event that a diver loses their oxygen supply while submerged, the first recommendation is to continue to breathe air while investigating the situation. This action is crucial because it allows the diver to remain conscious and alert while assessing the problem, avoiding an immediate ascent that could lead to complications associated with sudden changes in pressure.

Additionally, breathing air provides the diver with a stable source of gas that can prevent hypoxia, which is a dangerous condition that occurs when the body doesn't receive enough oxygen. By maintaining calmness and using the air supply available to them, the diver can evaluate whether the situation can be remedied, such as identifying the location of the oxygen loss or preparing for a controlled ascent.

Acting hastily by ascending immediately can lead to serious risks, such as decompression sickness or barotrauma, particularly if the diver has not taken the time to ensure a safe ascent protocol. Exploring the circumstances of the oxygen loss while using the available air supply increases the chances of resolving the issue without escalating into a more severe emergency.