I was running dual computers last week and went back into log mode checked, both showed a consistent 82 F. Neither temp sensor has been checked for calibration so the accuracy is ??. What I did find unusual was that on multiple occasions just over the walls I saw a noticeable thermocline, it was only a couple degrees but I could definitely feel it and see the visible shimmer at the transition line. A couple of times I saw schools of reef fish out feeding on the line, 10-20 yards off the wall, it was pretty cool. In the past when diving in Cozumel have rarely see this, normally the temp was consistant. I was able to get in 22 dives with 27 hours bottom time, can't wait to get back, in 2 weeks.