Yesterday, I can tell you, I was happy to have an instructor with me.
We swam down very rapidly and there was a strong current. All the sudden I started having trouble breathing. We were at 36m. Well, I thought, this is weird, I haven't been putting out enough effort to be out of breath. Another three meters down and I thought, this is wrong; I need to tell Daniel (the instructor) that I have a problem.
If any of you are divers, you know that the CO2 toxicity can happen in a few seconds. I'm not an experienced enough diver, and I guess I didn't pay enough attention during my level two training, to have had the reflex to completely empty my lungs. The CO2 toxicity was aggravated by narcosis, which can alter your perceptions and make you do stupid stuff.
Well, I go Daniel's attention and he started taking me back towards the surface. My hands were trembling and my fingertips felt like they were on fire. I was having black flashes across my vision and difficulty getting a good breath. I wasn't afraid, however, because I was sure that Daniel would take care of me. I asked him to give me his underwater writing slate and pencilled the message: "Ce n'est pas le peur; c'est physique." (the title of this message) I needed to write that because, as I've mentioned before, diving scares me, though I haven't been scared in quite some time. I didn't want him to think I was panicking. If I'm panicked, I'll admit it, but it was important to me that he understand that this time it was not fear. It didn't help me relax and get my breathing under control to think that I had ruined the dive for everyone else.
We didn't get out of the water directly but continued the dive at 15m. We can a really cool crab (It was cream colored with darker speckles and had a very high-domed back, almost like the top of an egg. It burrowed vertically into the sand every time we uncovered it) and an enormous humpheaded (?) parrotfish. It was about three foot long and Daniel said it is a "little one, an adolescent."
So, the dive started off poorly, but finished okay.
Now I know what narcosis feels like and CO2 toxicity and I don't wish to repeat either.
BTW, the narcosis symptoms vary from person to person. J got blurry tunnel vision and felt light-headed.