I understand that the pressure of the water around you goes up, but isn’t your body, that’s mainly made of water, counteracting that? There is no pressure directly on your lungs no?
Free divers just go down with 1 big gulp of air and their lungs don’t collapse below afaik, so I don’t fully understand why you consume air that much faster underwater. (I have 100+ dives to my name, but never fully understood the physics behind it)
In: 3
> but isn’t your body, that’s mainly made of water, counteracting that?
Ambient water pressure increases and pushes on the body. That pressure is transferred all through the body including the lungs. All the weight of the water above the diver is pushing on water just outside of them, so why wouldn’t it push on the water inside them?
> Free divers just go down with 1 big gulp of air and their lungs don’t collapse below afaik
They do actually, they compress up to about half their size. Inhaling isn’t possible anyway because they only have that one breath.
> so I don’t fully understand why you consume air that much faster underwater.
Scuba divers need to inhale air that is at the ambient water pressure, in order to equalize the pressure on their lungs. The free diver has increased pressure inside their lungs from the full breath being compressed to half its size. The air tanks need to provide air at that same pressure and thus volume, meaning the deeper they go the more air is in a given volume of breath.
Edit:
> (I have 100+ dives to my name, but never fully understood the physics behind it)
Dude, that is a *problem*.
> but isn’t your body, that’s mainly made of water, counteracting that?
Ambient water pressure increases and pushes on the body. That pressure is transferred all through the body including the lungs. All the weight of the water above the diver is pushing on water just outside of them, so why wouldn’t it push on the water inside them?
> Free divers just go down with 1 big gulp of air and their lungs don’t collapse below afaik
They do actually, they compress up to about half their size. Inhaling isn’t possible anyway because they only have that one breath.
> so I don’t fully understand why you consume air that much faster underwater.
Scuba divers need to inhale air that is at the ambient water pressure, in order to equalize the pressure on their lungs. The free diver has increased pressure inside their lungs from the full breath being compressed to half its size. The air tanks need to provide air at that same pressure and thus volume, meaning the deeper they go the more air is in a given volume of breath.
Edit:
> (I have 100+ dives to my name, but never fully understood the physics behind it)
Dude, that is a *problem*.
>I understand that the pressure of the water around you goes up, but
isn’t your body, that’s mainly made of water, counteracting that? There
is no pressure directly on your lungs no?
There is indeed pressure on your lungs. Freedivers breathe air at sea level pressure. The increased water pressure as they descend compresses their bodies which in turn compresses the lungs. Same volume of air + smaller lungs = more pressure. Freedivers can certainly experience lung injuries from pressure if they go deep enough.
None of this applies to scuba divers because scuba divers are breathing air at the ambient pressure.
>I understand that the pressure of the water around you goes up, but
isn’t your body, that’s mainly made of water, counteracting that? There
is no pressure directly on your lungs no?
There is indeed pressure on your lungs. Freedivers breathe air at sea level pressure. The increased water pressure as they descend compresses their bodies which in turn compresses the lungs. Same volume of air + smaller lungs = more pressure. Freedivers can certainly experience lung injuries from pressure if they go deep enough.
None of this applies to scuba divers because scuba divers are breathing air at the ambient pressure.
Latest Answers