"Over-breathing your reg"?

[ndboi]

"Over-breathing your reg"? What is this? Is this breathing during a panic situation? How can this be prevented and what do you do if this happens? Can this be caused by equipment? Under what conditions does this typically occur?

 

[knowone]

When you are jogging and become over exerted you can stop and take a breather.

When you are diving and become over exerted you sometimes cannot stop and take a breather.

 

[ndboi]

huh??

 

[Rhone Man]

Over breathing your regulator is sucking on it harder than it can effectively deliver the gas. Usually happens when you over exert yourself. Really it should be called over breathing the diver, but because high performance regulators deliver gas better than cheaper regulators, we like to pin our poor management as divers on a lack of better quality equipment.

 

[Akimbo]

Over breathing your regulator is sucking on it harder than it can effectively deliver the gas. Usually happens when you over exert yourself. Really it should be called over breathing the diver, but because high performance regulators deliver gas better than cheaper regulators, we like to pin our poor management as divers on a lack of better quality equipment.

Looking at test data, I believe your statement on high performance versus cheaper regulators is overstated in recreational diving conditions. I have seen evidence that most claims of over-breathing regulators are not valid. More often individuals get in such an anxious state that they don’t feel they get enough air, a condition well known outside the diving community.

Exacerbating conditions include wetsuits that fit too tight around the chest and diaphragm, hydrostatic pressure differential between the lung and second stage regulator, poor physical condition, mild claustrophobia, cold water, overheating under physical exertion, and situational stress. Most inexpensive regulators, generally referring to unbalanced first and second stage mechanisms, produce very high flow rates at very low demand pressure differential — at least above 500 PSI supply pressures.

It has been 20-30 years since regulators were marketed that were truly low performance. There are a number of expensive balanced first and second stage regulators that do not outperform their unbalanced competition. Comfort in the water and good physical condition are infinitely more important to safety than regulator performance.

 

[flots am]

Looking at test data, I believe your statement on high performance versus cheaper regulators is overstated in recreational diving conditions. I have seen evidence that most claims of over-breathing regulators are not valid. More often individuals get in such an anxious state that they don’t feel they get enough air, a condition well known outside the diving community.

Test data is pretty much irrelevant. There are a ton of regulators that need service, don't get it, and breathe like crap. It's entirely possible to "overbreathe" one of these.

This isn't to let overwork, CO2 problems, anxiety and panic off the hook either, however you can't just state that regulators aren't an issue because of the test data.

Flots.

 

[TSandM]

The term "overbreathing your regulator" is supposed to refer to reaching a respiratory rate that the regulator simply can't provide. In practice, this is all but impossible. What DOES happen is that, as a result of overexertion or anxiety, the diver raises his respiratory rate. Given that regulators -- even the best ones -- increase work of breathing, as the diver reaches a less efficient ventilatory pattern, CO2 climbs. The diver feels anxious and short of breath because the increased CO2 causes an increased ventilatory drive. The obvious conclusion is that the regulator isn't delivering enough air, when in fact, it's delivering everything that is asked for.

Heavy exertion is always something to be avoided on scuba. If you ever get the feeling that you just aren't getting enough air, STOP and rest. If that means grabbing a rock to stabilize yourself, do it. High CO2 heightens narcosis, causes anxiety, and predisposes to panic. Stopping, breathing quietly, and thinking can prevent accidents.

 

[Akimbo]

Looking at test data, I believe your statement on high performance versus cheaper regulators is overstated in recreational diving conditions. I have seen evidence that most claims of over-breathing regulators are not valid. More often individuals get in such an anxious state that they don’t feel they get enough air, a condition well known outside the diving community...

Test data is pretty much irrelevant. There are a ton of regulators that need service, don't get it, and breathe like crap. It's entirely possible to "overbreathe" one of these.

This isn't to let overwork, CO2 problems, anxiety and panic off the hook either, however you can't just state that regulators aren't an issue because of the test data...

I didn't write that regulators aren’t an issue, which is why I used "most claims of over-breathing…" and "More often individuals…" rather than stating it was always the case.

Service can be an issue, but it applies to expensive and inexpensive regulators equally. It has been argued that more complex balanced second stage regulators are more prone to performance degradation from infrequent service, but I have not seen any data supporting it.

From my limited sphere of visibility, regulators that need service usually have extremely low inhalation resistance — because they leak and free flow. Some service procedures will reduce inhalation resistance, usually cracking pressure, but rarely have much impact on peak flow rates that define over-breathing failures. If you study Scuba regulator design, there isn’t much that can reduce peak flow rates beyond a visibly clogged first stage inlet filter or a fantastically rare spring failure.

However, the cases I have read about where regulators involved in accidents and near accidents were tested in preparation for law suits, they all performed within specification. I have also read reports indicating that successful liability claims against Scuba regulator manufacturers are extremely rare. There are lots of contributing reasons unrelated to quality of design and manufacture, but it is an indicator that regulator performance is not a common cause of accidents.

I only entered into this discussion because I believe that safety arguments are used far too often to subtly coerce people into buying high-end regulators. I have no comment when people choose to buy expensive regulators for personal satisfaction, status, or styling. I completely agree with Rhone Man's overall conclusion, it was only a quibble over a part of his argument.

… Really it should be called over breathing the diver, but because high performance regulators deliver gas better than cheaper regulators, we like to pin our poor management as divers on a lack of better quality equipment.

 

[captain]

Looking at test data, I believe your statement on high performance versus cheaper regulators is overstated in recreational diving conditions. I have seen evidence that most claims of over-breathing regulators are not valid. More often individuals get in such an anxious state that they don’t feel they get enough air, a condition well known outside the diving community.

Exacerbating conditions include wetsuits that fit too tight around the chest and diaphragm, hydrostatic pressure differential between the lung and second stage regulator, poor physical condition, mild claustrophobia, cold water, overheating under physical exertion, and situational stress. Most inexpensive regulators, generally referring to unbalanced first and second stage mechanisms, produce very high flow rates at very low demand pressure differential — at least above 500 PSI supply pressures.

It has been 20-30 years since regulators we marketed that were truly low performance. There are a number of expensive balanced first and second stage regulators that do not outperform their unbalanced competition. Comfort in the water and good physical condition are infinitely more important to safety than regulator performance.

You nailed it.

 

[DeepSeaExplorer]

It is possible to overbreath a regulator. I did it once on a working dive trying to drag 30 feet of chain and 150ft of 3/4 rope along the bottom at 130ft during a wreck salvage job. This was back in the late 1980s and the reg was probably 20 years old then. That experience is why I have nothing but ScubaPro MK20s now. I know there's no way I can overbreath one of them. So maybe it isn't a concern under normal diving conditions with modern regs, but that doesn't mean it's never happened.