OP
Me or the Reg?
- Thread starter ScubaCatgirl
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A couple of things worth noting.
There is a lot of emphasis on reducing SAC rate, but that concern is often badly misplaced. One member posted the connection between CO2 retention and CO2 ralted headaches caused by the vaso-dialation that occurs. It is a very wise comment as a CO2 headache will ruin your whole dive day as they can be very persistent.
More importantly, CO2 retention can increase your susceptibility to nitrogen narcosis and oxygen toxicity. The US navy did expereiments with enirched air (nitrox) in the 1950's and opted not to use it operationally due to the unpredictibility of those two problems. In retrospect it was found that the major problem was that they had was that their test divers were almost to the man hard hat divers who, given the poor ventilation of the Mk V diving helmet used at the time all had a very high CO2 tolerance. Consequently I get real nervous when recreational divers start talking about reducing their SAC rates in the same paragraph where they talk about using nitrox. It's a bad combination as the higher O2 available in nitrox creates the opportunity to really prolong the time between breathes and really elevate CO2 levels.
Someone else mentioned that often a regulator will be adjusted too light and will freeflow air slightly between breaths. This can be a huge waste of air. My advice is to use an efficient pattern of breathing where you inhale fully, pause, and exhale completely and during the "pause" listen for even a slight freeflow or escaping bubbles. Then if present detune the reg only to the point needed to get them to stop. This point varies depending on your orientation in the water (normal swiming position, looking straight down, looking up, floating vertically in the water, etc) so the reg will need to be readjusted if you change orientation. And don't be tempted to extend the pause more than a few seconds as CO2 build up will result.
The rest of reducing your SAC is just using economy of motion, being as streamlined as possible, taking advantage of a glide between kicks and being as relaxed as possible underwater. If you are doing all that already and have a reg that is properly adjusted and still need more bottom time - just get a bigger tank.
There is a lot of emphasis on reducing SAC rate, but that concern is often badly misplaced. One member posted the connection between CO2 retention and CO2 ralted headaches caused by the vaso-dialation that occurs. It is a very wise comment as a CO2 headache will ruin your whole dive day as they can be very persistent.
More importantly, CO2 retention can increase your susceptibility to nitrogen narcosis and oxygen toxicity. The US navy did expereiments with enirched air (nitrox) in the 1950's and opted not to use it operationally due to the unpredictibility of those two problems. In retrospect it was found that the major problem was that they had was that their test divers were almost to the man hard hat divers who, given the poor ventilation of the Mk V diving helmet used at the time all had a very high CO2 tolerance. Consequently I get real nervous when recreational divers start talking about reducing their SAC rates in the same paragraph where they talk about using nitrox. It's a bad combination as the higher O2 available in nitrox creates the opportunity to really prolong the time between breathes and really elevate CO2 levels.
Someone else mentioned that often a regulator will be adjusted too light and will freeflow air slightly between breaths. This can be a huge waste of air. My advice is to use an efficient pattern of breathing where you inhale fully, pause, and exhale completely and during the "pause" listen for even a slight freeflow or escaping bubbles. Then if present detune the reg only to the point needed to get them to stop. This point varies depending on your orientation in the water (normal swiming position, looking straight down, looking up, floating vertically in the water, etc) so the reg will need to be readjusted if you change orientation. And don't be tempted to extend the pause more than a few seconds as CO2 build up will result.
The rest of reducing your SAC is just using economy of motion, being as streamlined as possible, taking advantage of a glide between kicks and being as relaxed as possible underwater. If you are doing all that already and have a reg that is properly adjusted and still need more bottom time - just get a bigger tank.
OP
ScubaCatgirl
Contributor
To my fellow divers. I thought long & hard about bumping this up on the board, but for safety reasons I thought it should be brought to everyone's attention. Especially new divers just setting out.
But before I go any further, I want to make it perfectly clear that I DID NOT bump this thread up to bash any of the divers who gave such wonderful advice. Were all here to help each other, right?
I also want to make it clear that it was NOT bumped up to bash up the manufacturer of the reg. That was why I was particularly vague on the name & manufacture of the reg to begin with when I couldn't figure out why I was going thru so much air when I had never done so before.
Thus the main purpose for me bumping up this thread is to try & return the favor by reinerating what we all learned in OW. Trust your instincts!!!!! I absolutely knew w/o a doubt there was something wrong with the reg. I talked to the divers on the boat after the dive & they all said naaahhhhh. Thus the 1st thread of doubt set in. But when I got back I put in a call to the manufacturer & he verified that yes, if the reg was tuned to high that would cause me to go through to much air. So off it went to their factory for them to detune. I checked it once it was returned to me & it breathed on the surface just fine. You guys know the rest of the story w/me going to the lake & STILL going thru way too much air & it still making a god awful honking noise. But doubt had taken hold of me (even though still in the make of my mind) I'm almost positive it's the regulator, but just to be sure I ask the question of this thread on the board. Everyone's advice sounded right on, so by then I truly believed I was the problem.
Folks, please, please, please. Listen to that little nagging voice in the back of your head, even if everyone else is telling you otherwise. It may save your life someday. And I thank god that I did call the manufacturer when I returned from vacation. Apparently, I am one of the reports that exhibited uncontrolled flow of air to the 2nd stage (forcing air down my throat).
Fellow divers, if you feel something is wrong. Ask questions, call the manufacture & if it still doesn't feel right, keep pressing. I didn't continue pressing cuz I was finally convinced it was me rather than the 1st stage that was recalled. It's a scary thought returning to the depths of the ocean with a regulator not working properly.
Fellow Divers, do as your taught in OW..........Trust your instincts!!!!!!!!!
But before I go any further, I want to make it perfectly clear that I DID NOT bump this thread up to bash any of the divers who gave such wonderful advice. Were all here to help each other, right?
I also want to make it clear that it was NOT bumped up to bash up the manufacturer of the reg. That was why I was particularly vague on the name & manufacture of the reg to begin with when I couldn't figure out why I was going thru so much air when I had never done so before.
Thus the main purpose for me bumping up this thread is to try & return the favor by reinerating what we all learned in OW. Trust your instincts!!!!! I absolutely knew w/o a doubt there was something wrong with the reg. I talked to the divers on the boat after the dive & they all said naaahhhhh. Thus the 1st thread of doubt set in. But when I got back I put in a call to the manufacturer & he verified that yes, if the reg was tuned to high that would cause me to go through to much air. So off it went to their factory for them to detune. I checked it once it was returned to me & it breathed on the surface just fine. You guys know the rest of the story w/me going to the lake & STILL going thru way too much air & it still making a god awful honking noise. But doubt had taken hold of me (even though still in the make of my mind) I'm almost positive it's the regulator, but just to be sure I ask the question of this thread on the board. Everyone's advice sounded right on, so by then I truly believed I was the problem.
Folks, please, please, please. Listen to that little nagging voice in the back of your head, even if everyone else is telling you otherwise. It may save your life someday. And I thank god that I did call the manufacturer when I returned from vacation. Apparently, I am one of the reports that exhibited uncontrolled flow of air to the 2nd stage (forcing air down my throat).
Fellow divers, if you feel something is wrong. Ask questions, call the manufacture & if it still doesn't feel right, keep pressing. I didn't continue pressing cuz I was finally convinced it was me rather than the 1st stage that was recalled. It's a scary thought returning to the depths of the ocean with a regulator not working properly.
Fellow Divers, do as your taught in OW..........Trust your instincts!!!!!!!!!
halocline
Contributor
I'm not sure I follow. You got your reg de-tuned and it lowered your air consumption?
I suspect Scubacatgirl has an Oceanic regulator that has been recalled. There was a problem with some of the high pressure seats disintegrating and allowing too high a pressure to the second stage. There are other regulators that received the same seat from the same vendor and have the same problem.
What concerns me is that she had to contact the manufacturer rather than the other way around.
couv
What concerns me is that she had to contact the manufacturer rather than the other way around.
couv
OP
ScubaCatgirl
Contributor
Your absolutely correct Couv. I was going thru air cuz of the recalled regulator and was trying to find out why. I had never been a major air sucker, even way back in OW class. I had quit smoking 6 months prior to the vacation where I used the regulator. Which, from what I had always heard was an advantage to increasing your bottom time. Instead, now I'm running for the boat before the newbies, 1 of whom I'm looking out for. Something was definately wrong! But I let myself get swayed, did not trust my inner voice & continued to dive w/a piece of equipment that was not safe.
Now in defense of Oceanic, I'm assuming they were not aware of this problem & I happened to be one of the divers that contacted the manufacturer about air being crammed down my throat. Thus alerting them to a potential problem so they could put out a recall notice.
And I will say again. This post was not brought to the forefront to point fingers at anyone. I just wanted to remind everyone to listen to that inner voice of theirs. It's there for a reason.
I want everyone to dive safely and live a long & happy scuba life!
halocline
Contributor
So it's not that the reg was detuned; it had a 1st stage problem which was fixed. De-tuning a reg simply means increasing the cracking resistance of the 2nd stage.
Either way, I'm glad you got it taken care of.
Either way, I'm glad you got it taken care of.
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