Safety stop : to do or not when panicked?

[Lorenzoid]

I would just like to add something that puzzles me about this thread....

It seems to me that the question is asking for the proper, well-thought out procedure that a diver should follow while in a state of panic. I'm confused. The two situations seem to me to be contradictory.

Now that I read it more carefully, I see the apparent contradiction. On my first read, I had interpreted it simply as: "I lost my nerve (maybe not quite 'panic') and blew off a safety stop; should I flagellate myself over it or just move on and learn how to be better prepared for this kind of dive?"

 

[doctormike]

CO2 is certainly a component of narcosis, along with nitrogen. Trying to isolate one from the other is pretty tough. Introducing helium reduces gas density and helps reduce co2 retention, and therefor narcosis (along with reducing the nitrogen component).

Not being narked and not noticing you're narked are two different things. Doing the same dive on air or nitrox then doing it on trimix is pretty eye opening.

Yeah, maybe I am always a bit narked at those depths and don't realize it...

I guess it's just a tradeoff, since adding helium to my tanks would - in addition to requiring more training, which is fine - make a big difference in my ability to dive every weekend, as it would be harder for me to get tank fills. Not saying that it isn't "worth it", just that it would significantly reduce my dive count.

The reason that I did my tech training was to spend more time at moderate depths (90-130) rather than to go deeper, so I'm OK with nitrox for now.

 

[RJP]

The warm, happy, euphoric narc is pretty rare in cold, dark water. What is far more common, at least here in the PNW, is free-floating anxiety and tunnel vision -- lack of situational awareness. One of the things my husband does with the deep dive for his AOW class is to tell the students they are to log their depth and pressure at five minute intervals through the dive. Funny, at about 80 feet or so, most of them start forgetting to do it . . . That's narcosis, and can end up with severe anxiety when somebody realizes they are much deeper than they want to be with the amount of gas they have left, just as you did.

It was good that you did not panic. It was good that the ascent was controlled, and that you made a conscious decision not to do the safety stop, although it appears you probably could have, if you could have calmed yourself at that point.

You nailed most of the lessons here. A dive plan should include a gas plan, and although I do not plan all dives on rule of thirds, as Joel mentioned, I do always calculate a "rock bottom", or the amount of gas that needs to be reserved to get me and my buddy from the deepest point of the dive to the surface, sharing gas. Had you been a little more distracted, you might well have ended up in that situation -- did your buddy have enough gas to get you home? These are important things to consider, particularly on very deep dives like this one.

Based on preliminary read on the data from a recently fielded survey, the OP is not alone when it comes to splashing without a dive plan or a gas plan. Just posted a few quick data points here...

http://www.scubaboard.com/forums/ba...ive-your-plan-preliminary-survey-results.html

 

[scagrotto]

It seems to me that the question is asking for the proper, well-thought out procedure that a diver should follow while in a state of panic.

I'm inclined to think that any diver who has enough gas should make a safety stop. Similarly, they should make a slow and controlled ascent to the safety stop. If you can do it any panic you experienced is almost certainly under control.

the OP is not alone when it comes to splashing without a dive plan or a gas plan.

I'd suggest that just doing a dive and paying attention to your computer and SPG is a dive plan. How good a plan it is depends on the purpose of the dive (is it a simple recreational dive, or is there a mission to be accomplished?), how well you monitor remaining gas and NDL, and whether or not you know enough to start your ascent with enough gas (regardless of how you make that determination). Without looking at actual data I'm going to make a SWAG that such plans are in excess of 99.99% effective.

I'd probably answer never or rarely to the first question. I don't need to know ahead of time what my NDL is in order to ascend before exceeding it, so I don't need o check it while I'm still on the boat. Based on the diving I've been doing I'll have a rough idea of how much time I have, and it's always generous enough for the dive I'm about to start. The same is true for the 2nd question. I don't need to do any calculations to know that the roughly 78CF I'm normally starting with is enough to spend 10 minutes or so at about 100', start working my way up, and head to my safety stop while I've still got enough gas.

In the case of the OP, the dive had a specific mission at a known depth, but the majority of dives aren't like that. The OP also seems to have had a plan, but failed to adequately monitor his computer. If the people who took the survey are mostly doing wreck dives in the northeast or cave dives in Florida the responses would be alarming. If it's divers going to the tropics and playing follow the leader with a DM it's a completely different story.

 

[JS1scuba]

Inert gas narcosis is insidious. The physiology of it causes the brain to process information more slowly putting one into a stupor. Jacques Cousteau described it as the "rapture of the deep” and coined the facetious gas law, “Martini's Law." Stating that when diving on air each 50 feet of depth has an equivalent effect of drinking one quick, dry, martini. This dive is equivalent to 2.4 martinis.


This particular situation that we have been discussing for a few posts still rolls back to the initial causes of poor planning. The time at depth was minimal. The partial pressure of nitrogen was only 3.66 atm PN2 while a small narcotizing dose, it is not overly significant. What may be important is that when the narcosis set in, the window of safety had already begun closing. Had there been proper planning, and appropriate gas supply and proper gas rules followed the narcosis at this level would not have been a significant factor. It would have been a non-issue.

 

[Iralub]

Can narcosis cause panic? As far as I remember, narcosis symptoms are at the opposite (feeling drunk, too relax..)

my only dive experience that I clearly associate with being narced involved significant and somewhat irrational anxiety, although not quite panic level. In a reverse of your situation, I was checking my gauge every ten seconds or so (due to anxiety). This was on a 40m dive that I had no business doing at that stage of my dive experience, but decent viz and much warmer water than you had.

 

[houlejon]

Did you do much of a surface swim? Were you exerted on the boat? .

We do right next to our boat (pontoon) . We didnt have to fin at all !

---------- Post added August 24th, 2015 at 08:42 PM ----------

I would just like to add something that puzzles me about this thread....

It seems to me that the question is asking for the proper, well-thought out procedure that a diver should follow while in a state of panic. I'm confused. The two situations seem to me to be contradictory.

I did asked myself the same question... or how much control do I have to prevent panic...!

---------- Post added August 24th, 2015 at 08:50 PM ----------

I just came out of the dive shop. I asked them to test my regulator (Oceanic EOS). Initial test revealed the cracking pressure was too high (I was told they had a reading of 1.7...)
They couldnot do further check since they are not trained oceanic dealers.. I will go to another DS to have it checked.

 

[JS1scuba]

Can narcosis cause panic ? Some of the symptoms of inert gas narcosis include: visual disturbances, perception narrowing, euphoria, etc. Much of this has to do with slowing down information processing in the brain. When information slows down so does everything else. Think about when one cannot find something important and they are pressed for time. Imagine you are about to get on a plane and you can't find your ticket. All of a sudden everything else becomes a blur and you only think about the ticket. Yet, one can function albeit poorly. Is this panic or is it a redirection of focus ? True panic is a serious disorder. And from what you have described you were just surprised at the information you saw once you recognized it. As I recall you were using a small digital air integrated watch style computer. Regardless of the brand, watch type DCs they are always difficult to read when vision is impaired. It is one reason why the clear-reading SPG is preferred. The numbers are less important than the position of the needle. Far right = good. Straight up = Good. Far Left = Bad. It works like the gas gauge on your car. Simple and easy to understand. Cheers