"chilly" 63 degrees? That's summertime water temps for us...
If you're going to do your AOW in Coz, it will really pay off to do your homework in advance. By that I mean not only read the chapters and complete the Knowledge Reviews, but arrange the details with the shop: exactly which dives you will have planned to do on which days.
In Cozumel, a deep dive and drift dive are part of the normal routine; that is, you're not sacrificing any "vacation dive time" to accomplish those. But the navigation dive will have to be done somewhere out of the current and in shallow water. You don't want to sacrifice a morning to do that when you could be taking a regular dive trip to see interesting stuff. Better if the nav dive can be done sometime (like in the afternoon) when you wouldn't have been doing a regular dive trip.
Find out what options are available for the remaining two dives. If they try to sell you on a "boat dive", just know they're not giving you your money's worth. Every dive you do there will be a "boat dive", and so you'll pick up everything you need to know whether you're in an AOW course or not.
A night dive would be very useful; I always try to include this in my AOW courses.
And a shop that really wants to provide you with a valuable course will suggest either a "peak performance buoyancy" dive or a fish identification dive. The fish ID dive is often panned, but if it's done properly it can be very worthwhile.
It would also be useful to get the performance requirements for each of these dives in advance, so you know exactly what your instructor should be doing with you on each dive. The deep dive is not just a "follow me, we're going to 100 feet". All of the dives have explicit requirements that connect with the material in the book.
Overall, the more preparation you do for the course, the better experience you'll have.