Slower loss of breath while underwater, when not mining/moving?

It is easier to hold your breath when you're not moving, at least in my experience, so the idea would be that you do not run out of breath as quickly while you're not actively moving (which would not count sinking, which happens automatically) or mining blocks. This could be helpful in a way by allowing us to be underwater for longer periods of time, since looking around can, collectively, waste a lot of time and breath.