What is the primary purpose of a pressure gauge on a scuba tank?

The primary purpose of a pressure gauge on a scuba tank is to monitor remaining tank pressure. This device provides divers with essential information about how much air is left in the tank, which is crucial for ensuring their safety while underwater. Knowing the remaining pressure allows divers to plan their dives effectively, managing their air consumption and deciding when it's time to ascend.

By keeping an eye on the pressure gauge, divers can avoid situations where they run out of air unexpectedly, which could lead to dangerous scenarios. The gauge typically reads in psi (pounds per square inch) or bar, giving a clear indication of the air supply available for the dive. This knowledge is vital for proper dive planning and execution, as it directly impacts how long a diver can stay underwater and at what depths they can safely explore while maintaining a reserve of air for ascent and emergencies.