If you had vis of "40 ft at best", you hit a VERY unusual day in Cozumel. I've been going to Cozumel regularly, at least once a year, often 2 or 3 times, since I got certified in 1990. From 1992 to 2004, I went for a week every March, staying at a timeshare in the old Plaza Las Glorias (now the Cozumel Palace), diving at least 5 days, usually 6, in those weeks. I estimate that I have over 350 dives on Cozumel, and I can count on one hand the dives where vis was less than 100' plus.
Why do I like Cozumel? First, it's incredibly convenient for me - I live in Dallas, and Coz is only a 2 hour 20 minute flight each way, and in most of the years I've been going there, I could always find very cheap flights. In the early years, when vacation charter companies were much more active, companies like FunJet, Apple Vacations, WorryFree, etc., I could occassionally take 3 or 4 day weekend trips to Coz with RT Air at $149 or lower. Those days are over, but you can still find bargains from DFW if you look. Second, I'm old, fat and out of shape, and I LOVE drift diving. The most relaxing, easiest, least exerting diving there is. Yes, I've been diving in other locations, from Moorea in French Polynesia (great pelagic life - sharks and Mantas on nearly every dive, but hard work doing fixed mooring dives), Grand Cayman (GREAT visibility, but VERY expensive to stay, eat and dive), U.S. Virgin Islands, Martinique, but Coz is my favorite. Third, I really, really like the diving, and not just because drift diving is easy. Coz has a wide variety of dive sites, with comparatively good coral life (yes, the coral really took a hit with Hurricane Wilma in 2005, but its really coming back), great structure (like Palacar Caves and Palancar Bricks), and a lot of wonderful sea life, like the Hawksbill Turtles, the Morays, the Toadfish, and a wide variety of reef fish - I still get excited over seeing a juvenile Trunkfish, looking like a little dark blue die, shaped like a cube and with those bright spots. Fourth, Coz has a lot of choices for both Hotels and dining in nearly every price category. I've done the super bargain trips to Coz, where I stayed at $19 a night hotels, ate three meals a day on $25 or less, and spent most of my money diving with Aldora, a higher end Valet Dive Op with steel 120 tanks and 1 hour plus bottom times. And Coz has some (many!) really wonderful restaurants, to the point where I can stay 10 days, never eat in the same restaurant twice, and still miss some of my favorites. Finally, but definitely not lowest on my list, Cozumel is one of the friendliest, most genuinely warm (emotionally, not temperature) vacation places I've ever been to. I go back year after year, seeing the same people at favorite restaurants, and they greet me not like a tourist with money to spend, but like a friend. You can't buy that.
