It’s not about keeping parts ‘inflated’. It’s about being able to fill your lungs with gas by creating a lower pressure space in them than the surrounding environment. This means more pressure your lungs have to work against the deeper you go. The regulator delivers gas to your mouth at a slightly higher pressure than the water around you, so that your lungs can overcome that pressure difference and you can breathe in. This takes more pressure from the regulator the deeper you go, which also means a higher volume of gas required to fill your lungs. That’s why your tank runs out faster the deeper your dive is.
It’s not about keeping parts ‘inflated’. It’s about being able to fill your lungs with gas by creating a lower pressure space in them than the surrounding environment. This means more pressure your lungs have to work against the deeper you go. The regulator delivers gas to your mouth at a slightly higher pressure than the water around you, so that your lungs can overcome that pressure difference and you can breathe in. This takes more pressure from the regulator the deeper you go, which also means a higher volume of gas required to fill your lungs. That’s why your tank runs out faster the deeper your dive is.