[Req] No Radio outside of sub

[Grey_Raven75]

A minor quibble, but is there any way to make the radio only audible when you're inside the sub? I love listening to the radio, but it's a little weird when I'm on the bridge or out on the deck and the radio is as audible as if I were standing next to it. Doesn't seem to be a way to affect this with the Radio.ini Is there some other way to change the volume depending on your position in/on the boat?