What is an independent action to take in response to an out of air emergency?

In an out-of-air emergency, performing a controlled swimming ascent or an emergency buoyancy ascent is crucial for diver safety. This response allows the diver to ascend in a controlled manner, which helps to avoid rapid ascent and the associated risks of decompression sickness and barotrauma. By carefully managing buoyancy and ensuring a slow ascent, the diver can also monitor for any potential issues while ascending to the surface.

The other approaches, such as immediately surfacing without managing buoyancy may lead to serious complications due to rapid ascent. Creating a bubble signal is not a recommended independent action, especially if the diver is low on air and requires immediate attention. Waiting for assistance, while prudent in certain situations, does not provide an active solution to the immediate problem of running out of air. Therefore, executing a controlled ascent or buoyancy ascent stands out as the most practical and responsible independent action to ensure safety in an out-of-air emergency.