If you haven't picked up on it yet, Cozumel options involve trade offs. There is probably not one "ideal" location or dive op. There are a great many choices, and what is best for you depends entirely upon personal preferences. If you insist on a dedicated Dive Resort, there are really only two, Scuba Club Cozumel and Blue Angel, and neither has a beach to speak of. If you insist on a big resort with a beach, there are several, all well south of town, all AI, all convenient to the dive sites, but very inconvenient to the great restaurants in town if you discover that your AI resort has only marginal food. The in-town hotels, like Casa Mexicana, are very convenient to the restaurants and night life of downtown, but limit your choices of Dive Ops to those that pick up downtown or will transport you to the Caleta (but there are a few very good dive ops that will pick up downtown or transport you to the Caleta), none are convenient to beaches. Those in the "near downtown" area south of town, like Hotel Cozumel, are a short walk to downtown (15 minutes or less), with more of a "resort" feel. Others down near the International Pier, like Casa Del Mar, El Cid, etc., are a cab ride from downtown, but much closer to the beaches, and more Dive Op options. I personally love Cozumel as much for the great food choices and friendly people as for the diving, so I do NOT do All Inclusive resorts on Cozumel, and I prefer staying either downtown, a short walk from downtown, or at Casa Del Mar, but no farther south. Others are more into diving and less into food and culture, and may select one of the big AI resorts way south. It depends upon what you want from a Cozumel vacation. As to Dive Ops, again, there are a hundred good choices, with different options - what do you like? A big boat with lots of socializing, or a quick six-pack? High end valet service, or just give me a tank and weights and I'll take care of myself? Big steel tanks, long dives (1 hour plus) and long SI on the beach, or 45 minute dives on AL 80s where you get back to the Hotel by noon? You generally do NOT have to use the house dive op, though some resorts will charge you a pier fee to let other dive ops pick up at the hotel pier, and i have my own set of favorite ops, but then so do most of the other posters in this forum. The question is what criteria are important to YOU in a dive op?