From my post #174 "Trimix I'm sure is great but it isnot essential for deep diving." This would indicate correctly that I have zero trimix experience. I never claimed any. I do claim many years, many dives, and manyhours diving deep on air before trimix was available to the general public and before tech diving had a name. The Navy, Cousteau and commercial divers werethe only divers using mixed gas when I was diving to the bottom at Castle Hill Newport,RI charted max depth 200fsw all though I never found that hole. One can’t dive with gas that’s not available. Back then I was doing what every other sportdiver diving deep was doing, the best I could. I never had the money to pursue trimix training and the required equipment. I don’t dive deep anymore been there donethat. Around here in RI unless it’s a wreckthere is nothing to see below 80fsw expect mud and broken shells.