Here's the list. Editorial comments are mine since I started this thread with my disgust. I think the top dive operators in Cozumel are: Aldora, Liquid Blue, Blue XT, Living Underwater (not in any particular order) because they all offer diving more tailored to the diver's experience (including very advanced diving if they deem you capable), 3 of them offer larger steel tanks and I think Blue XT offers them on request (I'm sure Chirsti will correct me if I'm wrong), very long BTs, fast 6-pack boats, excellent DMs and captains, long SIs (usually at a beach club or beach). Price has nothing to do with my top choices. The fact that some of the best dive shops on the island were excluded bothers me.
1) Aldora (which is similar to the group in my original complaint)
2) Aqua Safari - big-azz boats and lots of newbies
3) Dive House - mostly big boats (I have spoken to divers who complain of short bottom times and baby dives)
4) Dive Paradise - mostly big boats, a few smaller ones
5) Dive with Martin - they have an Experienced Diver boat which might be as good as my top list, but they also have a lot of newbies on larger boats.
6) Papa Hogs - their small boats with twin Yammies are fast. They also have some big boats
7) Sand Dollar Sports - don't know anything about them
8) Scuba Cozumel - mostly big boats
9) Scuba Du - they have a good reputation.