In what situation is it necessary to use a rescue tank?

Using a rescue tank is essential when a distressed diver has exhausted their air supply or is incapacitated. In such situations, immediate access to an alternative air source can be life-saving. The rescue tank serves as a backup supply, ensuring that both the rescuer and the distressed diver can breathe safely while ascending to the surface or reaching a safe area where further assistance can be provided.

This action directly addresses a critical need—providing breathable air when the main source has been compromised, which can prevent potential drowning and respiratory complications for the distressed individual. A rescue scenario often demands quick thinking and decisive action, making the availability of a secondary air source paramount for effective emergency management.

In contrast, the other scenarios described do not present an immediate risk of air supply exhaustion where a rescue tank would be necessary at that moment. While performing routine checks or assisting inexperienced divers may require attention and care, they do not typically involve the same urgency or criticality as the need for a rescue tank in a situation where a diver is incapacitated or out of air.