max depth?
- Thread starter hantzu701
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You can have one and not know it, and if you do, and its bad enough, virtually ANY dive can bend you - no matter how careful you are.
People with that problem simply shouldn't dive unless they have it fixed. Unfortunately, for most people who do have it they find out when they get bent "for no reason." Fortunately, a PFO that's bad enough to cause trouble (not all are!) is reasonably rare.
People with that problem simply shouldn't dive unless they have it fixed. Unfortunately, for most people who do have it they find out when they get bent "for no reason." Fortunately, a PFO that's bad enough to cause trouble (not all are!) is reasonably rare.
the problem with it is that if its "open" and you bubble, even a bit, you've got MAJOR problems.
See, most of us bubble when we get out of the water. Hopefully not much, but a small amount. And its normally ok, as the lungs are really good filters, and lung tissue is one place where restricted blood flow (at least at the capillary level) isn't too damning, since the tissue has direct oxygen transfer from the air.
However, if you have a PFO, and bubble even a little bit, then those bubbles can bypass the lungs and go straight to the arterial circulation. That usually means a Type II DCS hit, and often an "undeserved" one.
There are many "degrees" of PFO. Most people that have them have ones that are "closed" more-or-less, and open only under extreme stress. This is why forceful clearing on ASCENT or anything that causes "straining" like that is a really bad idea.
If you have one that is normally "open", then you're one of the people who will probably get bent some day for no obvious reason at all.
The problem with detecting this is that the test to do so is neither cheap nor risk free, so unless you have a reason to get tested (e.g. you suffer an "undeserved" DCS hit, especially a Type II one) its very difficult to make the case for being tested "prospectively."
See, most of us bubble when we get out of the water. Hopefully not much, but a small amount. And its normally ok, as the lungs are really good filters, and lung tissue is one place where restricted blood flow (at least at the capillary level) isn't too damning, since the tissue has direct oxygen transfer from the air.
However, if you have a PFO, and bubble even a little bit, then those bubbles can bypass the lungs and go straight to the arterial circulation. That usually means a Type II DCS hit, and often an "undeserved" one.
There are many "degrees" of PFO. Most people that have them have ones that are "closed" more-or-less, and open only under extreme stress. This is why forceful clearing on ASCENT or anything that causes "straining" like that is a really bad idea.
If you have one that is normally "open", then you're one of the people who will probably get bent some day for no obvious reason at all.
The problem with detecting this is that the test to do so is neither cheap nor risk free, so unless you have a reason to get tested (e.g. you suffer an "undeserved" DCS hit, especially a Type II one) its very difficult to make the case for being tested "prospectively."
diverjed
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Dive deep, dark, and dangerous!
RichLockyer
Guest
Actually, 22 feet is the limit where you will not saturate to a dangerous level, but the limit for 33ft is much longer than you could stay on one tank.
Theoretically, you could get bent on multiple repetitive dives to 33ft.
ew1usnr
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Pressure is relative. Which brings to mind diving at high altitude. 33-feet of seawater equals one atmosphere pressure (14.7 psi), .... at sea level. At high altitude atmospheric pressure is less than 14.7 psi, and an equivalent one atmosphere pressure of water column is correspondingly less than 33-feet. The depth gauge, once "zero-ed" for that altitude will provide equivalent, not actual depth.
Diving in fresh water will allow a little bit deeper no-decompression zone than does salt water. Most gauges are calibrated for salt water. When a gauge reads 33-feet, you are probably actually a little deeper if you are in fresh water. The gauge shows the equivalent salt water depth.
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