I just wanted to post what we've signed up for, in case others were curious. We can hardly wait for July!
Cozumel - Opal's Dream, 2 tank boat dive. (They have an unfortunate history, but they're willing to hold a boat for us until we get there from the cruise ship, the reviews on tripadvisor are excellent, and we've received very friendly customer service so far.) We hired a DM for the two of us, since this will be our first boat dive, first time in salt water (weight checks), and first time with potential currents.
Grand Cayman - Shore diving. Probably 2 dives, either Eden Rock/Devils Grotto, or Sunset House. Since it's just shore diving we can decide which one to go to later. (BTW, what's the name of the dive operator at Eden Rock?) We're undecided on hiring a DM for that. If you have a particular DM to recommend for this, please do!
Roatan - We'll spend the day with our family, doing a Victor Bodden private tour (if you can call 30 people from our extended family private). We'll snorkel West Bay Beach, see the monkeys, and get a good lunch.
Belize - Turneffe Atoll 2 tank boat dive. We'll probably hire a DM for the two of us for that too.
We're bringing a bag of scuba gear apiece now - we added our own regulators and BCDs. Wish us luck finding room for all of our stuff in our 4-person room on the ship!