Hi everyone, I am curious here. I went diving yesterday and think I got super lucky I followed my dive computer. First dive I was down 47 ft for 59 minutes. Simple right leaves me in pressure group C. Then, my fiance and I got out of the water, went to lunch for a bit, had a surface interval of 3 hours 20 minutes. Then we went out to a different dive site. This time visibility was absolutely terrible and I went a little deeper than expected. We went down 78 ft (at that depth for about 12 mins) and when I noticed how deep we were we went up to 35 ft for a bit hung out there, did a 10 minute deco stop at 15 ft then ended our dive. According to my dive computer total bottom time on this dive was 68 minutes. I am doing my Dive log and am very confused. According to this we should be dead. Here is what I am factoring please tell me where my calculations are wrong. 1) 47 ft Down for 59 minutes puts us at pressure group S 2) Surface interval of 3 hours 20 minutes puts me at pressure group A. 3) Assuming our residual nitrogen time at 80 ft in pressure group A is 4 minutes, and we then went down to 80 ft for tbt of (68 + 4) 72 minutes, I don't understand. The RDP says 80 feet for 30 mins is pressure group R with mandatory 5 minute decompression stop. I more than doubled that according to above. Can someone explain to me why we are fine and what is wrong with my calculation? I watched my computer nitrogen calculator cautiosly when we were hanging out at 15/20 feet.