My wife and daughter were in Puerto Morelos in mid October for a mother-daughter vacation and dived with Dive in Puerto Morelos for 3 days. They had a fantastic time and appreciated the valet dive services provided. My wife and I had the opportunity to return in mid-December for a family wedding. My own requirements for a dive operator are more stringent than my wife's and daughter's and I do not require the assistance they appreciate. Dive in Puerto Morelos really delivered and I had a great time on 7 dives over 3 days. DM Carlos was great in leading the dives and not overly controlling in his technique. Capt Cornelio had the uncanny ability to stick with the drift diving group. The reef dives had most of the usual Caribbean suspects, unfortunately, including Lionfish. The wreck of the C-56 was increcible with squadrons of Eagle Rays, Southern Rays, Amberjack and other reef fish. The swim throughs were great.
I don't think you could do better than diving with Dive in Puerto Morelos. Enjoy your stay in this laid back location and enjoy your diving.
Best, Craig
PS On our visit in December the water temps were 75-77*. We used 5mm full suits and were quite comfortable for hour dives. Check the water temps and make sure you are appropriately protected.