I've gotten a headache while diving before, but who knows what caused it. People get headaches. It doesn't necessarily mean anything. But it does pique my curiosity.
I understand the feeling. Headaches on dive trips are often caused by skip breathing and/or dehydration - a minor irritation if you don't pass out from one or take a hit from the other. I've never had one but seen others suffer.
Sometime in the last few years I started learning about CO possibilities tho, the risks and some known losses, the lack of prevention common at many destinations, even the lack of postmortem testing and I started looking for better answers. I can see why this has not been well examined on Scubaboard before as one runs into too much old school resistance, defensive crap from pros who don't want to bother, and while finding the info hasn't been easy - it's been rewarding in ways.
Finding a portable analyzer that tests in such very low ranges was a challenge but I found one. I've since learned its weak points and how to avoid them, as well as how to actually test in the field, what bags to use for that model - and the manufacturer has since produced a modified model with appropriate accessories (Pelican box, the best test bag) and software specifically for scuba testing.
While it took me a few trips to work out the kinks, and me wondering if I was wasting time, getting real readings will get your attentions. :shocked2: The first time you get a 5 is a wake-up; getting 17 can be unnerving. Don't let a long string of zeros get to you; it's good practice.
I remember a dive shop trip to Belize once when the first day most of the group got ill after two dives and didn't make the third. I thot they were a bunch of city wusses who didn't adjust to the tropics quickly and shrugged it off at the time.
As the days passed, I learned how crappy the local Op was, and at the end of the week learned a bit about air testing from the other Op that supplied the Nitrox but still didn't make too much of it. A few years later, talking over that day with the shop and my home bud, it occurred to me that it was only the air divers who got ill, not the Nitrox users - but that basic difference didn't explain the difference? Now I wonder if the crappy Op realized what had happened, quietly drained his tanks and cleaned his compressor, and how close we came to first day tragedies back then. We'll never know, but - well, hope my feelings make sense.
When I first got my CO analyzer, I loaned to that same shop for their trip to Utila. They forgot they had it until they had another first day of sick divers, then tested, then forced the Op to drain tanks and clean the compressor. After flying that far to dive, you don't want to just quit so you try to make it work - and they did.
I don't know that we'll ever see wide spread monitoring and testing across the sport/industry as DAN is still seemingly avoiding taking up the gauntlet. I wish they would, and they might. I've actually exchanged some communications with their CEO, really nice fellow obviously to take my phone call for starters, and he sounded interested - just not proactive, to my knowledge.
With more and more divers carrying and using CO analyzers tho, then reporting problems here on SB, and now two manufacturers producing new portable units easier for even more to use, some knowledge will be acquired - and hopefully more compressors cleaned up before hits or losses. Hehe, now that DAN's magazine runs ads, I hope to see Analox advertise their new unit there.
We'll never know how many lives this saves, but we will see somethings in the months to come I bet.