Alarming and Dangerous Incident please read

[TheRedHead]

I had a dive where my valve was turned off and cranked back half a turn and my reg breathed fine until it just stopped. I think it is a simple case of overbreathing his regulator. The urge to breathe isn't controlled by O2, but by CO2.

 

[Stu S.]

Have you called DAN? Seen a doctor? Maybe your problem is not related to diving. I have a good friend who had a similar problem ... on dry land. Once the doctors got it figured out he received a heart pacemaker at age 39.

 

[GDI]

What are the standard signals for difficult breathing?

The older divers would know that a closed fist tapping against the chest indicates difficulty breathing and Low on Air for todays divers as compared to a slice action across the neck for out of air

The build up of CO2 can contribute to the effects of narcosis (and DCI) as well as other issues.

Bismark may have also given you insight into your equipment status of a question I would also ask and was thinking about when reading this thread. To me it sounds like you may not of had the valve open correctly and this could produce similar affects in your difficulty in breathing. Add to this perhaps fatigue and a deceptive workload while under water. Your own very excitement going into the dive may have caused you not to open the valve correctly, it doesn't take much. Thus the deeper you went and the longer you stayed the more air your body will demand. Your breathing unconsciously increases as does the demand for more air and before you know it you are having difficulty breathing.

I don't think narcosis was the problem here, not at that depth range of 75 ft for someone with 118 dives under their weightbelt.

 

[RonFrank]

IMO one of a couple things happened...

You were definately in a panic state. Was this a result of narcosis? That is difficult to answer. The fact that you started rushing to the surface when you had two buddies with you that both had air indicates a state of panic, and impacted judgement. Panic is not uncommon, and most that experience it may never understand why other than scuba does put one in an environment where we can not live without technology!

Hypoventilation - under breathing to the extent that the blood carbon dioxide level is elevated; may be manifested by carbon dioxide narcosis.

Hyperventilation - condition where an individual breathes too rapidly and has a lowered CO2, lowered Ca++ with the production of tetany; usually due to panic.

Others have discussed the various options. Doing a controlled ascent with a buddy was the right choice, but one you did not make. In this case you would have wanted to do a controlled ascent with TWO buddies.

Glad you are OK.

 

[Ber Rabbit]

I don't think narcosis was the problem here, not at that depth range of 75 ft for someone with 118 dives under their weightbelt.

I respectfully disagree with this. Maybe the OP wasn't narced but it was indeed possible; I had a dark narc diving air at 70 feet on the Regina in Lake Huron. I recognized what was going on, refused to drop my reg and bolt to the surface like my head was telling me; instead I signalled my buddy and we ascended a few feet at a time. I was at 50 feet before the feeling went away. I've been narced on an air dive that had a max depth of 40-50 feet, I was watching students on their final dive and couldn't figure out why they had stopped in the shallows--it was because they were doing their safety stop, I had no clue. I dove to 135' on 27% once and was narced out of my mind, my buddy had to drag me by the hand to a shallower depth. You don't have to be deep to be narced though, there are a lot of other factors that can contribute to a narcosis hit. I never noticed being narced until after I had almost 300 dives although I'm sure I was to some extent. The more I dive the more I notice the impairment from the nitrogen.
Ber :lilbunny:

 

[Scubakevdm]

I was diving the Tracy in about 75 ft of water off the coast of Ft.Lauderdale, Florida. I had two diving buddies. When we reached the wreck, conditions were good, not great - 40 ft visibility, light current. I was on Nitrox at 36% which was checked at the shop. Upon reaching the wreck I began to expirience a shortness of what seemed oxygen in the mix. I was getting all the volume I demanded of my regulator (Scubapro S600) yet felt like it was not oxygen. Confused I swam towards one of my two buddies which turned into a dash due to the increase deficiency of oxygen. Despite the standard signals I gave him for difficult breathing all I got was a spaced out look from him. Oblivious to what was unfolding right in front of his eyes. At this point I pointed straight up with my hand and bolted up in a semi "controlled panic". I knew that something was deadly wrong, I knew I needed to breath and I needed to reach the surface. I also know that my chances for survival would be in my favor risking the bends or embolism to reach the surface. I was leterally sufficating. At about 30 ft from the surface immediately I started to feel like the oxygen was returned and quickly returned to normal. I went back dowm to find the two individuals diving with me to let them know I was OK and to do a proper gassing off ascent. It seems like I was sucking on nitrogen. Can the gasses separate or layer off in the tanks? I know for a fact that the shop owner does not roll tanks to get proper mix as did the previous owner. Any suggestions, recommendations are deeply appreciated.

Peter

You don't need to roll the tank, it'll mix all by itself.
Here are some points that I wonder about:
How much experience do you have diving at that depth? Some people are more easily narced than others. It may be something that wyou will have to keep an eye on.
Someone mentioned that the EAD for the mix was 55 feet. This is good for determining nitrogen loading, but oxygen is similar to nitrogen as far as it's narcotic properties. Helium is commonly used to displace nitrogen for the purposes of lessening the narcotic effects of breathing gasses. You may find that if you are sensitive to narcosis that a recreational tri mix course might be a solution.

Another issue that would play out in a scenario like the one that you've described, would be one where a diver fails to open his tank valve enough. At deeper depths, where there is an increased demand for flow the partially open valve restricts the gas. At shallower depths with a lesser reuirement for flow it may allow enough gas past it.

 

[lamont]

CO2 hit is my guess.

A mostly shut valve could also be to blame. Gases also get thicker and if your first stage isn't balanced the differential between your IP and ambient will drop causing your second stage to breathe harder. Combine that with the onset of normal N2 narcosis at 70-80 fsw (about where I start to notice short term memory issues creep in), and then excertion and the whole panic cycle starting up, along with CO2 buildup and you've got a nice CO2 hit going. And all of the possible factors I just listed would lessen as you ascend...

My best guess is probably that your reg is cheap/rental and the decreased efficiency of gas delivery, combined with high demand due to you being a new diver made it hard to breathe. With the N2 narcosis that let you get a paranoid edge and start worrying about "insufficient O2" which really let the panic cycle take off. Then you built up CO2 which made the narcosis, and the rapid breathing worse, which reinforced the feelings of paranoia and panic. Ascending wiped away a lot of the narcosis and let the reg breathe easier.

Get a better reg, make sure that your valve is all the way open, and take it slow and easy... When you notice that you are breathing heavy try to take controlled deep breaths. You don't want to breathe rapidly, but you do want to take full inhales and then exhale completely to expell the CO2 in your lungs.

 

[LavaSurfer]

Sounds like CO2 retention to me. It can precipitate a dark narc which makes it harder to slow down the breathing and that contributes to more narcosis. If you feel yourself not getting enough oxygen again, make an effort to stop, be as still as possible, and focus on taking deep, slow breaths and exhaling all of the air out of your lungs. It is a shallow, panting type breathing that starts this process, and once it starts, it is very hard to stop.

Glad to read that you are ok.

I wonder that a slight current, some level of work, maybe hyperventalation and then blowing off too much CO2. Causing a panic attack of sorts augmented by the possibility of Narcosis.

 

[DandyDon]

Is there a chance that you didn't have your tank valve opened all the way? If you just cracked it on the surface to read the pressure on your spg, and then did not open it completely before diving, you would experience difficulty breathing as you descended. This would appear to you like an out of air incident which would get better as you ascended. Also, you can notice this if you watch your spg when you breath and notice a pressure drop on each breath.

He said: " I was getting all the volume I demanded of my regulator (Scubapro S600) yet felt like it was not oxygen. Confused I..."

He was narced with panic complications. Like Walter said, its' measureable at 33 ft, adn depending on a lot of variables, could happen at 75.

In a bad or out of air situation, he should have grabed his bud's alternate reg, but in this state - didn't think of it, I guess. I rarely use my slate, but keep it handy, yet with panic setting it, that may not have helped either.

First and foremost thing to do is get positive, so he handled it well in that area.

 

[TheRedHead]

I wonder that a slight current, some level of work, maybe hyperventalation and then blowing off too much CO2. Causing a panic attack of sorts augmented by the possibility of Narcosis.

Level of work and current will certainly contribute. Friday I was diving Punta Sur at 100 feet and had to kick hard across a strong current. I wasn't used to the heavier size L jetfins I was wearing and I went from mildly narced to uncomfortably impaired and was breathing hard. I just stuck my fist in the air had my buddy hold until I could slow down my breathing. It had a definite affect on my level of narcosis for the entire dive - like belting down a couple more martinis.