Odd event at depth

[flots am]

We do what is, for us, a rapid ascent (I think it took three minutes or so to get to 15 feet, where we spent about a minute, and then ascended.) On the surface, Peter told me he thought he had bad gas. He got a bad, oily taste at depth and began to feel nauseated. It got worse over a couple of minutes, so he wanted to have someone else's gas to breathe, to see if he felt better. He told me my gas tasted much better, but he was still nauseated and that's why he thumbed the dive.


Bob and I both breathed his gas once we got back to the car, and neither of us could detect anything odd.

Noses are terrible at reliably detecting contamination. Bob could have been smelling something nasty from a sinus infection or from actual bad air, and conversely, just because you didn't smell anything doesn't mean the gas wasn't contaminated.

If you still have the tank, you could always send a sample out for analysis. It would be interesting to find out what if anything was wrong with it.

flots.

 

[TSandM]

Well, the particular reason why I immediately thought this was a drill was that I have been asking my buddies to do drills with me recently, because I've gotten rusty (as this incident clearly illustrated!) So I just thought Peter was cooperating . . .

With respect to the SMB, I think how you view that depends on how often you use them and how facile you are with it. I was basically taught that, any time you have to do a no-reference ascent, you should shoot a bag. I have shot a lot of them, and done things like air-sharing ascents while controlling a maskless diver and managing a bag, so I'm not very worried about getting tangled up in it or having it affect my buoyancy control. But I AM susceptible to vertigo in midwater, and the last thing I want to do is start doing somersaults with someone on my gas who HAS to be there. For me, in the dark, the bag is by far the better choice.

Flots, as I posted some time back, the gas is being sent out for analysis, from that tank and also from the other tank we picked up that day (which had not been used).

 

[Peter Guy]

DD -- where we were diving is just a few hundred feet from a boat launch/fishing pier and we were out far enough that it would not be inconceivable for a boat to be coming in.

I would not want to ascend where we were without having either a line for reference OR an SMB to warn potential traffic.

 

[DandyDon]

I'll be looking closely to see how much that new Analox CO analyzer will cost.

Not enough to worry about I bet. Their first unit was a little over $300 so I bet the new one will be similarly priced. It'd be nice if one buddy could supply the Nitrox checker and the other the CO tester, instead of me having both - but my bud is loaning me $1,000 of tools I don't want to own for a couple of weeks. I get back at him now and then.

This incident may well have not involved CO, and there are many possibilities, but it'd be the first thing to check for. We have reliable, portable testers available, and it seems to be a common risk even tho not well appreciated by many long time divers. We used to not have the technology and they did their best.

There has been some claims as to how reputable the fill station is, but none about an inline CO monitor, and I gather from the replies that a portable CO tester was not either.

 

[dumpsterDiver]

DD -- where we were diving is just a few hundred feet from a boat launch/fishing pier and we were out far enough that it would not be inconceivable for a boat to be coming in.

I would not want to ascend where we were without having either a line for reference OR an SMB to warn potential traffic.

I'm not sure that an SMB would provide much protection from boat traffic at night unless it was lighted and even if it were lighted, it might serve more as an attraction to curious boaters than a warning. I'm sure that is a very good reason to stay submerged and to swim up the slope which was the correct decsion in my mind.

As I said before, if I did NEED an SMB, then my personal preference in a real emergency would be to get the victim up to say 15 ft and THEN mess with the reel and deployment. From this depth, if things go south, the recuerer could just man handle the victim and drag them to the surface.

This hesistancy to ascend with zero reference is something that is 180 degrees to my experience and perspective. When I was a young teenager, I remember being scared and hesitant to venture too far from the anchor line when wreck diving in NJ (in bad vis, dark water) because I hated swimming up alone with no reference, it was "scary".
After a few years of diving, I was able to develop the situational awarness to ascend solo in bad vis with no reference, no big deal. I personally feel that it is a basic skill necessary for safe diving.

I understand that if someone is extra susceptible to vertigo, then the ascent line becomes more than a casual preference. To me, that is not a huge "accomodation", but my personal preference would be to not "need" it if an emergency that requires direct ascent occurs. What if Peter had started to "Tox out", go into convulsions etc.? this would probably require the recuer's full attention and the smb reel would be discarded.

 

[Ayisha]

Please do post the results of your gas analysis when you get them, Lynn and Peter. I hope that it was not bad air, but if it was, that is a scary thought...

Is there any way you guys could push for in-line CO monitors at dive shops in the U.S.? Even state-by-state if not country wide? Also more stringent requirements in the level of CO in recreational air tanks than the current 10 ppm?

It is possible. Here in Ontario, it has been pushed by the Ministry of Labour for all recreational dive shops to have in-line CO monitors over the last couple of years, so almost all of them do. All my LDS's have inline CO monitors. The max acceptable level of CO in compressed air for recreational divers is 5 ppm (0 ppm for commercial). The in-line CO monitor requirement for recreational dive shops is supposed to be written into the regulation by this December, so hopefully that will become official.

Whatever the testing shows, this is a good opportunity to really think about legislating in-line CO monitors in the U.S. and other countries. The dive shops are not going to want it - the divers have to demand it! And show your support for those shops that have an in-line CO monitor with your wallet...

 

[TSandM]

DD, not many people out there have had the problems with vertigo that I have had. At one point, I was fairly sure that I would never be able to cave or tech dive because of it. I have much better coping skills now, but I would prefer not to need them. Shooting a bag at depth was going to take one stressor out of the situation for me -- I would have a reference for vertical. As I have said before, one doesn't have to spool up the line while ascending -- it can be pulled up from the surface at the end. If Peter needed physical assistance during the ascent, I could let go of the line. If I lost it, that would be one more step into the incident pit . . . but that's a lot of failures.

I have previously demonstrated the ability to perform rescue skills in midwater (for my tech class) but that was in daylight. At night, I could probably do it, but why not hedge my bets?

Anybody who dives with me knows about my vertigo issues. I don't hide it.

 

[Peter Guy]

I actually have no idea if the LDS has an inline CO monitor -- nor do I know if the O2 supplier has one when filling its O2 bottles.

IF there was contamination (and I really think the most likely situation is that I ran into something OR I just hallucinated!) it is unlikely we'll ever know if the issue was the compressor at the LDS or the O2 supplier.

 

[DandyDon]

I actually have no idea if the LDS has an inline CO monitor -- nor do I know if the O2 supplier has one when filling its O2 bottles.

IF there was contamination (and I really think the most likely situation is that I ran into something OR I just hallucinated!) it is unlikely we'll ever know if the issue was the compressor at the LDS or the O2 supplier.

Well, honestly - I know that y'all regard the shop highly, but untested gas is unknown. More of a risk in the tropics, but still...?

 

[dumpsterDiver]

DD, not many people out there have had the problems with vertigo that I have had. At one point, I was fairly sure that I would never be able to cave or tech dive because of it. I have much better coping skills now, but I would prefer not to need them. Shooting a bag at depth was going to take one stressor out of the situation for me -- I would have a reference for vertical. As I have said before, one doesn't have to spool up the line while ascending -- it can be pulled up from the surface at the end. If Peter needed physical assistance during the ascent, I could let go of the line. If I lost it, that would be one more step into the incident pit . . . but that's a lot of failures.

I have previously demonstrated the ability to perform rescue skills in midwater (for my tech class) but that was in daylight. At night, I could probably do it, but why not hedge my bets?

Anybody who dives with me knows about my vertigo issues. I don't hide it.

I think that is a reasonable emergency proceedure: attempt to quickly send up the smb and if things go south super fast on the bottom, then drop the reel and try to ascend along the line.

Of course, if this were to occur over a sloping bottom in a current, then the reel and smb could be drug into shallower water, allowing the line to go slack when the reel rests momentarily on the bottom which could facilitate entanglement during the ascent along a slack line. Then in my worst case scenario.... the reel snags on the bottom, while the loose line is wrapped around the victim and now the victim is being drug downward by the current because he is tethered to the bottom by the reel and the line.


Then again if all that were to happen on one dive, maybe your time was up anyway. I am just so paranoid of loose line in the water. I have seen so many problems occur that were almost unbelievable with divers and slack lines etc.