I made a mistake diving. It did not end in catastrophe. I was with an instructor and I mistakenly depended upon him to keep me out of trouble. We ended the dive in decompression mode and I sat for 18 minutes and he for 24 minutes at 10 feet. It’s a long story but I do not yet understand the conservative algorithm for my new dive computer. I knew it was warning me. I failed to go to the dive ceiling point and the computer penalized me. No big deal. I was out of air. I am not a fish in water. The usual dive buddy, also an instructor, saved us with a spare tank and we cooled our heels at ten feet. The water was relatively cold. Everyone around here has been staying away because it’s January. And of course, I set a personal record for time underwater, in the cold (shivering) at 101 minutes. It’s a lesson I shall not forget. Please don’t worry. We were smart enough to listen to the warning eventually and were never in true danger. Nonetheless, I question the physiology of the difference ten feet will make on nitrogen desaturation. I may question but I still follow the rule. Oh, the shot I have is the last shot I took before I headed to the decompression area, like the penalty box in hockey. Yup, I had to cool my heels. And brother, it was cold sitting around that extra time.