I would check with Blue Angel Dive Shop at the Caribe Blu Hotel in Cozumel. I just returned from there, and courses are taught right in front of the dive shop and hotel. The water is clear, there is a small rock ledge with lots of tropical marine life, and the water goes from ankle deep to around 23 ft. deep. The training platform is around 16 ft. deep. Two-tank boat trips for certified divers are $53 per person, per day, when staying at the hotel. Also, when staying at the Caribe Blu shores dives are unlimited, at no additional charge. Prices for everything were very reasonable, and the shore dives were great, including 3 night dives.
There were a couple of courses being taught while I was there, and I even finished certifying some of my own Advanced OW students that were on the trip with me during our stay. I do not know how much Blue Angel charges for referrals to finish courses, but I remember hearing that they do accept some referrals. If you do a search online for Caribe Blu, Cozumel, Mexico, then you will see all of the info regarding the hotel/dive shop/restaurant.
Jeanie (your online contact owner) is wonderful to deal with, and the entire staff was extremely pleasant to deal with. We thoroughly enjoyed an entire week staying with them, and diving with them. Please tell Jeanie that Barry and company referred you to them.
The cruise ships we saw that came and went every day only stayed in Cozumel for 10-12 hours (I think), so you should probably check and see how long your ship will actually be staying. When most people get there, they wish they had a couple of more days to stay because it is so beautiful, and the climate is so mild this time of the year. Air temp was 78-80, water temp was 74-78 depending on depth, and the humidity was low. There was always a slight to moderate breeze blowing to make the comfort level even better.
There was always a current everywhere we went that ranged from slight to strong, but it was mostly moderate and tolerable, so almost all open water diving is drift diving. Safety stops are made without reference (no anchor line or buoy line) while hanging in the current at 15 ft., so buoyancy control and proper weighting is of utmost importance. We did our dives with a little extra weight because of this due to all tanks being aluminum and, as you know, they become more buoyant near the end of the dive. Current for our shores dives was slight to moderate, and very tolerable.
I hope this helps some.