I cut and pasted below from another post, re my Cancun trip Dec, 2016. Jan is spotted eagle ray season, so that is nice.
I just came back from Cancun in early Dec. I only did 2 dives there, but they were good.
I dove the C-55 wreck & the nearby reef as a 2nd dive. We had hoped to do the C-58 but the buoy was missing. The C-55 (and the C-58) is at 80' and the current can be strong - so its an advanced dive. We ended up going down the line, but it is often a drift dive. Lots of eagle rays & lots of fish. Not much of a wreck, the C-58 is supposed to be better, but lots of life.
The nearby reef - I believe its called "No Name Reef" -- but its the reef that is generally done as a 2nd dive, was the highlight of my vacation. A ~60', drift dive. This was a great reef, lots of life, a baby bull shark, eagle rays, swam with a green turtle for a bit, an eel, a big Nassau Grouper, just tons of fish, and a very healthy reef.
I would recommend diving one of these wrecks (the C-58 is prob better) and the nearby reef. Unfortunately I didn't dive any of the more OW sites, so I cant recommend anything.