Just a quick note on Deep Blue COZ. My wife and I returned from diving 6 days with this outfit for the first time and while I wouldn't go so far as to say the operation was bad, we weren't impressed.
A little background: we first dove Cozumel 9 years ago as our first ocean trip after getting our certs. We dove with Martin, then and had a great time. Since then, we've hit someplace new every year or so as our schedules allow. We heard that since Martin's passing, the quality of service had declined so we rolled the dice with another operator who a) had been around a while, b) seemed to not have a lot of negative reports and c) had small boats.
I set up the arrangements via email with Gary (it's a very convoluted process, but I didn't have any problems with the deposit (half, via Paypal) or reservation process. Our travel dates were solid from the first communication. 8 days (sat-sat) in Coz, 6 days of 2 tank diving. He wanted to know about our experience level and recent dives, how many days we'd be diving, rental equipment, etc. He also wanted us to call him when we got in to reconfirm. So far, so good. When we got to our hotel room I found the phone ringing. Long story short, it's Gary and he thinks we've been on the island for 3 or 4 days already and haven't contacted him. Wanted to make sure we were still diving 3 days, and he had our rental BC sizes wrong. Got all that straightened out. I figure we'll be on the dock at 9:30 and a boat will either show up or not.
The boat showed up, and including us, it had 9 passengers, 2 DMs and a Capitan. No rinse buckets. A partial shade cover that covered the forward 6 pax. Those of us in the rear got the full sun ride. There was a little net suspended from the shade cover for dry storage. Luckily we bring a dry bag, because it was full up. There was no sort of safety briefing, particularly no mention of O2 or first aid on the boat. I saw the green O2 case strapped to the bow when they were docking, so I assumed it had a working bottle in it. The divers were a group of 5 with one DM and our group of 4 with the other. In spite of giving them our detailed diving history, we were stuck with a father/son duo who were, to put it mildly, very inexperienced. Luckily I only had to get smacked in the head and look at silt for about 25 minutes until they had to head up for their safety stop and we had the whole reef to ourself. They let you dive your computer and only ask that you hit your safety stop with 700psi. Snacks on the boat were bottled water, watermelon and bananas...Every. Day. Surface intervals were at a deserted beach with a dock that is used by several other operators. No shade, No banos. Get in the water to pee. After the second dive, the DM asked, "Are you diving tomorrow?" Si. In the morning? Si. This continued for the next 5 days.
Over our six days of diving we had 4 DMs. We had to constantly remind them what sites we had already dived. Except for the first and last days, the total number of divers was between 4 and 6, with us having 8 on Friday (with 2 DMs). For 4 of 6 days, we had at least one newby and/or freak in our group who had no business being in the water unsupervised. One guy hadn't dived in 20 years (he looked early 30's, so had to be a kid when he got certified) and he pretty much panicked and started flailing around underwater and almost grabbed my wife's reg out of her mouth. This other dude was an Eastern Euro Speedo wearer who refused to back-roll into the water and at the last minute would stand up on the gunwall of the boat, almost capsizing it, and giant stride in. Our bright-spark DM du jour launched us on a 120' dive with this wierdo and I didn't once see him ask about our air situation. After a while, I couldn't find our DM and started looking around for him. He's 40 feet above us with the Euro guy buddy breathing off him. That's a first for me. Being a small group, we could stay away from the bozos for the most part (when they weren't physically assaulting us underwater) and dive our own profiles, but it is still annoying to have to deal with that. A couple of days we did have a pretty squared away group and a good DM and the diving was just that much better because of it.
Anyway, that ended up being a lot longer than I had intended. Overall the diving was very good. We had flat seas, good visibility and hit The Cathedral, Mariceibo, and the Devil's Throat. The "customer experience" I would rate a solid "5". If it was a choice between them and a cattle car operation, I'd pick them, but with so much competition on the island (I counted 75 in the phone book) I am sure there is an operator that goes that extra mile to really earn your repeat business. Hope this has been helpful, and if not, at least entertaining.