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lung compression

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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New Member
Aug 17, 2004
I am waiting for my second set of lenses to come in for my liquid goggles, so today, although I went diving, I wasn't really focused on depth. Instead I tinkered around with Residual Volume dives using a weight line attached to a bouy. At about 25 feet I managed to experience my plasma shifting into my lungs for the first time. What a strange feeling. Strangest thing I have ever felt! Being such a foreign sensation, I thought I had hurt myself. I headed fot the surface with some moderate rapidity. As I ascended the feeling of pressure in my lungs didn't go away. When I hit the surface I took a breath, and everything seemed back to normal. There was a lingering sensation of pressure, like a memory. I was very nervous to repeat the experiment, but later in the day, I did so several times. Same effect each time. I never coughed up any blood, though after several hours I did experience some slight soreness in my lungs (not like it hurt to breathe, it just felt like my muscles were tired).

It is my understanding that not all people are cut out for depth. Some people's lungs can handle it, while other peoples capilaries rupture giving them a squeeze. I haven't really read that it depends on the person, I just sort of assumed it. In any case, I figure that I have crossed an important barrier into the unknown, and would like to know if my experience sounds like an accurate representation of this process, or if it sounds more like I got a squeeze and have misinterpereted the data. I figure it would be wise to proceed with caution rather than just assume that I know what happened and that I can now go as deep as I want.

Also, does anyone know anything about the transfer rate of plasma into the lungs? Do they fill up totally all at once, or does a little bit trickle in at a time until the lungs are full of plasma? Is there a maximum rate of transfer that would limit the rate of descent during the process of transferance? Or ascent?

I really appriciate all of the helpful feedback I have gotten from this community.

Under ideal conditions, the alveoli 'swell' with plasma, but no plasma actually enters the lungs. Generally, if plasma enters the lungs, then, upon surfacing, you will feel a persistant urge to cough, and perhaps a coughing urge if you try to exhale a lot. Further, your apnea ability is often degraded until the plasma clears (which takes about 12-24 hours for most people).

For that reason, I don't consider it 'normal' or desirable, although it is better than blood in the lungs.

Some people have generally flexible rib cages, flexible/relaxed chest muscles, and flexible alveoli walls (to swell easily). Those people can proceed deep quite quickly.

Other people are less flexible, and they must proceed more slowly, gradually over months or in some cases years.

A few RARE people (1 in 500 or less) seem to have a condition which forever prevents them from adapting to the pressure.

Generally, proceed slowly; half breath dives are much safer than exhale dives. Always descend extremely slowly on any half-breath or exhale dive, especially in the first 10m. Always have a buddy! Stop at any sign of coughing urge, blood spitting, or discomfort.

Remember that being tense, nervous, or cold all negatively effect your chest's ability to deal with pressure.

Eric Fattah
BC, Canada
It's hard to know what is going on inside of myself having not experienced everything. How does one tell the difference between swelling / leaking plasma / hemmoraging blood? I felt a sense of extreme weight, but not pain. I did not feel an urge to cough whatsoever. I was doing full exhale, and then mouth fills for various equalization purposes as I descended. I am just trying to do prep work on the experience before I start going much deeper. I am presently going to 20 meters without much effort, but I don't want to get down to 35 or whatever the heck and then find out I wasn't designed for it.
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