re: Best 7 day cruise? Western Caribbean? Southern Caribbean?

we have been in all three areas a number of times. We are divers as well but that is not our primary focus any longer. Western offers some great diving and you will see some green foresty areas as well as flat sand like Cozumel which I use to love 25 years ago. Central/Southern is good also for divers and non-divers alike. If you are focused on doing beachy type ports you will enjoy either and remember Roatan as well as Belize offer shore experiences in the mtns and rain forests. Eastern cruises especially out of PR that skip or minimize the USVI and BVI ports became our fav for the difference in the islands beauty and diversity, great. I say experiences as we don't book ship based excursions any longer as we have learned you can do more, with more flexibility and less expense and crowds going ashore and booking or on line before hand. Sometimes we just find the taxi stand boss lady and get a taxi for the day and say "take us". Those have been wonderful and more local experience.
Been blessed to see most of the Caribbean on cruises, week long stays land based and from a bare boat charter in the USVI/BVI which is fantastic and so different than VI port stops. We mixed business with pleasure in the Caribbean with our business before we sold it.
If I can help just let me know here on TD by sending me your email.

I have never done Southern Caribbean but I can say that if you do Western then I highly recommend the Cozumel, Roatan, Belize itinerary. Great stops. Roatan is amazing. Cozumel has plenty of things to do. Belize wasn't great but weather wasn't cooperating that day so I don't hold it against the port. Will be doing Jamaica and Grand Cayman in addition to Cozumel in a few weeks and will have done all the Western Caribbean itineraries.