Sorry to start here, but first a little about me. I am a 62yo Professional Engineer well experienced in objective observation and rational analysis. I took this cruise, 7 days through Grand Cayman, Roatan, Belize and Cozumel, by myself as a little private vacation.
It is unlikely in the extreme that I ever again take a Carnival (and maybe any other) cruise. While the personnel were cordial, respectful and hard-working, many were improperly informed and inadequately trained. For one shore excursion (Belize) I was twice sent to improper departure assembly points on the ship; finally, after some aggressive inquiry, I did find the correct place in time, but it was an unnecessary and unpleasant experience. A planned (and paid) excursion on Grand Cayman was missed when I used my telephone for a waking alarm as I often have. The phone time was correct with ship time when I went to sleep but was changed to later when I was awakened, and I missed the trip. Unknown to me, the time was reset by connection to a cell tower on shore when the ship approached port. Had I been advised of this possibility, I would have been on time for the excursion. The money for the excursion was refunded, but the opportunity - my principal reason for taking the cruise - was irretrievably lost. This was the first time, in my many overseas travels, when postcards I mailed did not arrive in the US; they were mailed with stamps purchased on the ship and were left in a mail drop which was to be mailed from our current port. Overall the crew was pleasant, but apparently not capable of being very helpful.
It was not such a great experience, and one I am unlikely to repeat. Oh, and one more thing... I have never been in any environment, and that includes various bars of many types all over this country, where there were so many people drinking to the point of incapacitation. There were many inconsiderate and unpleasant passengers.