The farther I get from that situation, the more I realize how fortunate we were. If we had known better, we would have objected immediately when the shop assigned 1 guide to 4 OW divers for a 100’ dive. I let my ego and the bragging potential overwhelm my common sense. It was dumb of me because of depth, conditions, using unfamiliar rental gear - including a computer for the first time with no explanation. It was even dumber of me to be so cavalier that when I saw that I was running low on air, I actually remember thinking to myself, "The guide will tell me when it’s time to ascend. This gauge is just a general suggestion." I’m not even embarrassed. That’s how dumb I was. I won’t be that dumb again. Nobody can get that lucky twice.