We've just returned from Cozumel Mexico with Carnival. The diving was great! And thanks to a great dive master, George, we saw wonderful reefs and wild life including some lobsters close to two feet long, a moray eel that was over 1.5 meters with a radius of about 12 inches, and an octopus coiled up in a small hole in the reef. Water clarity was wonderful with visibility well over 100 feet. I had never dived at Cozumel before the hurricane, but we saw no remnants of the hurricane. Maybe there it was better before, but I can only judge based on what I saw this trip and it was spectacular.
We were diving with the Carnival contracted dive company AguaWorld. They were a large operation with at least 3 dive boat but only took divers from the cruise line. They have no office, so no website or phone number. I would have gone with another company due to price, US$85 for two tanks, but I did not have time to arrange with another provider. Their boats were in good shape but no bathrooms and the diesel exhaust was overwhelming as you reentered the boat. Some of the divers were disappointed that no wet suits or lunches were provided. I am not sure wet suits were needed, (I had my own) as the water was reported to be 83 degree at 30 meters down. I did notice that most of the divers were cold after returning to the boat including one lady that came back so cold her lips were blue. I would have liked to have had a sandwich between the dives as I eat a very small breakfast prior to diving.
On shore we asked around and found quite a few companies that were offering two tanks between US$65 and US$75, but I don’t know when they would have been leaving and if they would be back in time for our departure.
Our dive master was great, but due to no food, no wet suits, and the boats exhaust, if going on Carnival, I recommend that you contract with a local dive operator prior to arriving at the site.