DCS??

[Imla]

For clarification, CO2 is a minor risk as long as there's plenty of O2 available, but I think you meant CO, carbon monoxide, which can be extremely dangerous. I don't guess that you tested the tanks before you dived them so were diving on hope alone. CO hits can mimic other risks and maladies so they're difficult to identify without immediate testing, of the environment or the patient's blood, but it is a possibility here.

However... CO2 fits really well with the symptoms he describes. Elevated respiratory rate, borderline panic-feeling. General feeling of crappiness and headaches afterwards.

 

[Tumbler31]

Hello @Tumbler31 ,

Can you provide more detail about the occurrence on Saturday's dive? At what point did the lightheadedness resolve? I share @smiffy6four 's concern about the potential for some sort of contaminated air, especially if you were diving with the same outfit each time. How are you feeling now?

Re your travel, it seems unlikely that your first event was related to DCS, so flying should pose little risk provided that you stay within published flying-after-diving guidelines and you have no other medical issues that could present as an in-flight emergency. If you're concerned, as @Lorenzoid posted above, a visit to a physician would be reasonable.

Also concur with @boulderjohn, who posted his reply before I finished typing mine, that anxiety is another possibility given the information you've provided.

Best regards,
DDM

Thanks for your response. Thursday and Saturday were actually with different operators - Thursday with a big operation, lots of divers going through on a time table (hence the 30 min SI), and Saturday was with a private operator who has a pretty state of the art filling system. I’m feeling a lot better now but when I dwell on it or look at the GoPro video of the aborted dive Saturday, I start to feel a little nervous, so it may all be in my head. I’ve never been anything but Joe Cool underwater (not bragging), so I find myself wondering if this will have lingering psychosomatic effects. Thanks again for taking the time to respond.

 

[Tumbler31]

However... CO2 fits really well with the symptoms he describes. Elevated respiratory rate, borderline panic-feeling. General feeling of crappiness and headaches afterwards.

Concur, but there were 18 or so other divers on the boat with the same nitrox.

 

[boulderjohn]

However... CO2 fits really well with the symptoms he describes. Elevated respiratory rate, borderline panic-feeling. General feeling of crappiness and headaches afterwards.

The source of problematic CO2 in a dive is close to never the breathing gas. The source is the diver's metabolism.

• Heavy exercise can create a backlog of CO2 that needs to be released through normal respiration. Normal respiration includes deep exhalations that remove the CO2 from the body.
• If the breathing does not remove enough excess CO2, then the general feeling of unease will grow and start moving toward panic.
• As that urge to breathe grows, the diver will breathe more rapidly. This can compound the problem, for the diver exhales faster than the CO2 can enter the air being exhaled. It is almost like putting a barrier at the top of the lungs.
• Because the body's urge to breathe is a reaction to CO2, the diver may develop a sense that the regulator is not providing enough air. The diver is nearing full-blown panic.
• This will too often result in the diver discarding a supposed non-functioning regulator.

Heavy exercise is not needed to start the COs-based panic cycle. It can stat through fearful, shallow breathing.

 

[Imla]

Concur, but there were 18 or so other divers on the boat with the same nitrox.

As @boulderjohn says above. The source of CO2 is usually the diver. So, if the other 18 divers had a good balance between ventilation and production of CO2, they would not have a problem with it.

 

[Lorenzoid]

@Tumbler31 , further to what @boulderjohn and @Imla said, CO2 accumulation can spiral (out of control in some cases). Someone might feel a little "off" and instead of calming down and concentrating on breathing fully, they get anxious (thinking about what could be causing that feeling) and breathe rapidly but shallowly, which prevents proper CO2 removal, and so on.

Don't confuse CO2 retention with breathing gas contamination (by CO, for example).

 

[DandyDon]

Typos are can lead to confusion and CO2 & CO are similar typing but totally different in effect.

However... CO2 fits really well with the symptoms he describes. Elevated respiratory rate, borderline panic-feeling. General feeling of crappiness and headaches afterwards.

Good answer.

Concur, but there were 18 or so other divers on the boat with the same nitrox.

Means nothing. For the CO risk, one tainted tank can show up right in the middle of a run of dozens of tanks being filled. One either tests each and every tank or gambles.

Don't confuse CO2 retention with breathing gas contamination (by CO, for example).

 

[Tumbler31]

The source of problematic CO2 in a dive is close to never the breathing gas. The source is the diver's metabolism.

• Heavy exercise can create a backlog of CO2 that needs to be released through normal respiration. Normal respiration includes deep exhalations that remove the CO2 from the body.
• If the breathing does not remove enough excess CO2, then the general feeling of unease will grow and start moving toward panic.
• As that urge to breathe grows, the diver will breathe more rapidly. This can compound the problem, for the diver exhales faster than the CO2 can enter the air being exhaled. It is almost like putting a barrier at the top of the lungs.
• Because the body's urge to breathe is a reaction to CO2, the diver may develop a sense that the regulator is not providing enough air. The diver is nearing full-blown panic.
• This will too often result in the diver discarding a supposed non-functioning regulator.

Heavy exercise is not needed to start the COs-based panic cycle. It can stat through fearful, shallow breathing.

Ok this Is spot on.
-pretty strong current, first dive in 4 months
-tried jet fins for the first time, totally different kick from my Volo Race fins that I’ve used for years
-used a BP/W setup for the first time, had to search a few times for a few things instead of them being naturally where I was used to

this all seems to add up to some mild exertion which may have compounded as the dive went on and anxiousness. I also constantly had salt water in my mouth, which was annoying and doesn’t speak well to how well the equipment may have been maintained.

thanks again! I really appreciate it!

 

[Tumbler31]

I can‘t thank you all enough for helping me understand this. I LOVE the continuous learning aspect of something that I am so passionate about. I am super grateful that you all took the time to respond.

 

[-JD-]

@Tumbler31 out of curiosity, did you have a bout of Covid recently?