My friend and I did this same itinerary last year and will also be on the Sky in January with the same ports of call, but with our spouses this time. Here are my thoughts.
My friend and I did the same “Relax on the Beach” in Roatan. The beach is very close to the port and the water was murky when we went. Also, there is row after row of clamshells which are nice because they provide shade, but the beach was extremely crowded. It’s not one I would do again. Roatan does have some nice snorkeling but it is on the West End.
In Belize we did the Xunantunich Tour with lunch. It was a long ride, but we loved the ruins and both enjoyed the lunch. We liked it so much we are doing the same excursion again with our husbands.
In Costa Maya and Cozumel last year we did private excursions. A cooking class and market tour in Cozumel (which we are also doing with our spouses this year).
In Costa Maya we did another set of Mayan Ruins and lunch in a Mayan village. With our upcoming cruise we are going the the 7 Color Lagoon with the same private tour company.
Hope that helps. Have a great time!