Just finished a week on the Sun. Dove the ships operator in Roatan and Belize. In both cases the groups were small and the operators good.
In Roatan, we dove with AKR. They had the very nice touch of having all guests check their buoyancy at the dock rather than waiting while somebody floundered around out on the dive site. Dive groups were small and the DMs generally led us around the reef, pointed out some interesting stuff and left us alone. My assigned buddy and I were allowed to dive until we got to 500 lbs and decided to surface. One dive was 57 minutes. Dive briefings were good and the boat (for just us cruise divers) had lots of room. Surface interval was spent back at the resort since the dive sites were only about 10 minutes out. A very agreeable experience.
Belize - as previously mentioned - includes anchoring well out from town. Hugh Parkey's Belize Dive Connection is the operator. They picked us up off the ship. Their boat had plenty of room. We stopped at their shop out on one of the atolls on the way to the dive site so folks could pick up rental equipment. Although I had my own, what I saw of the rental stuff was good. Excellent dive briefing, small groups with each DM and freedom to enjoy the dive was the order of the day. When someone ran low on air, the DMs let them go up with others of their kind and let those with plenty of air stay down. The DMs were especially good at pointing out hard to see stuff and making sure that we could get a picture.
Didn't dive Coz since I will be back there next month.
Grand Cayman really took a hit from the hurricane. We went on the Sting Ray experience. It was a cattle boat and a collection of heavy duty tourists. Sting Ray City was a zoo. That said, getting up close and personal with that many rays - who act like puppies, was an experience not to be forgotten. I recommend that you do it once. You can likely just ride the tender in and get a Sting Ray city tour on the dock for half the ship price.
The ship itself was well run, the crew excellent, friendly and helpful. The specialty restaurants were excellent and worth the $15 to use them. Breakfast on the fantail was great except for the damn smokers, but I guess they should get to smoke somewhere. I would not recommend cruising as a way to get the best diving experience, but it proved to be an excellent way to check out several destinations for future diving experiences - and my non diving wife had a great time as well.