I did those 3 ports plus Grand Cayman in October 2005 on Carnival.
Although I wanted to dive the blue hole un Belize my ex wanted to do a hike n tub ride which was cool.
In Roatan we went to Anthony’s Key Resort, they were fantastic. One of the best charters I’ve been on. We dove #15 Green outhouse wall and #24 Barry’s Reef.
In Cozumel the dive was right by the boat. Dove Santa Rosa Reef and Paradise Reef, which were both spectacular.
I was a seasoned diver, my ex only had 2 previous ocean dives and we both had a good time.