I have never been to Belize or Progreso, but Couzmel is nice. The water is so clear and blue, you can see all the way down to the bottom of the ship. Cool in my opinion. Couzmel seems like the most forign port that I have been to. Things arent as commercial there, so you really feel like you are on a tropical island. You can do alot of shopping, (I get stuck doing it w/ my sister) and snorkeling. You need your birth certificates only when you board the ship in your homeport (unless things have changed.) Have a good trip.