Here is a list of unhappy events that I survived and that were due to my own fault. Of course others have probably happened that I am not aware of, because I did not realize them.

Some months ago, back on the boat after a one hour and a half shallow dive in the Red Sea, I instinctively removed the oxygen manual injector in order to drain the water that could have accumulated in the expiration counter-lung before the next dive. Absolutely no drops fell down. I most often do not get much water but at least a few drops. This time total dryness ! That seemed very unusual and so I start feeling something wrong happened. I checked the other counter-lung : the water was there ! I instantly realized that I had inverted the position of the hoses and the mouth-piece and so transformed the expiration counter-lung into the inspiration one and vice-versa. I had absolutely no sign of malfunction in the water. I thought then and still do, that since I use quite low values for the high set-point (1.0 or 1.1) this inversion had little consequences on the level of PpO2 at different points of the breathing loop. However if I had injected manually oxygen in the loop, the breathed PpO2 could have been much higher than the measured one. Now that I dive with a bail-out second stage integrated in the mouthpiece and that the mushroom check-valves are in this mouth-piece bloc, such an inversion can not happen on the field any more … unless you mistake the check valves during maintenance and do not check its correct functioning afterwards.

More recently, on a deep dive (100 meters for 20 minutes), I planned to do a diluant switch during deco at 21 meters, from trimix 8/62 to nitrox 32 %. All the gear was properly set before jumping in the water with the 8/62 in the on-board 3 liters and the 32 % in a 10 liters tank side-mounted on my right hand side for open circuit bail-out. An inflator hose was running from the first stage on this tank to the manual inflator at the bottom of the inspiration counter-lung across my chest. The 8/62 was added to the loop through a Bob Howell ADV. On the left hand side I also carried a 10 liters tank with trimix 10/50 for bottom OC bail-out. The dive was wonderful and when I reached 21 meters I started pressing the 32% inflator to perform a nitrox diluant flush. Nothing happened, no mix was injected in the counter-lung. I checked : the valve was open, the pressure gauge was reading 220 bars, the hose was connected tightly to the injector. While checking this connection I manipulated the sliding ring on the connector fitting and the mix started to inflate the inspiration counter-lung. In fact I had to keep pressing with one hand on the connector to keep an inflating flow, the other hand pressing the injection valve. The fitting I was using was not an AP Valve inflation connector, it was a regular one and I had no problem to connect it to the inflation valve. When I tested it on land before diving it worked for the moment probably thanks to a particular conformation of the hose-valve assembly but in the water and on land after the dive it was not properly injecting unless I kept a significant pressure on the ring to stick strongly the fitting to the valve. I knew that most of the regular inflator hose connectors do not fit at all on the AP Valve injection valves but in my box of spares and old stuff I had found one that fitted but the flow was not established or very uncertain. So now I use an AP Valve connector to the mix that I plug at the bottom of the counter-lung when I need it that way.

On another dive, I performed a nitrox 32 diluant flush at 21 meters to blow out a 8/62 heliair and I heard the alarm ringing. I had a quick look at my hand-sets and the three cells were reading 2.55. I first thought the mix was wrong though I had checked it a few days earlier at the beginning of the diving week. So I switched to my open circuit integrated in the mouth piece for a few “sanitary breathes” on the 8/62 and performed again a diluant flush. The cells were still reading 2.55 and the alarm ringing. I was pressing the oxygen inflator …