I have to agree about Ocho Rios. "No I don't want any ganja" (at least not from you ) but I have to disagree about Cartagena. We walked away from the pier and took a cheapish taxi into the city center. From there we found a inexpensive tour to the mudbaths about an hour away. I will say seeing the skyline of Cartagena as we sailed out at 10 pm is one of the most vivid memories I have from that trip. Now Colon, Panama, that's scary!
I've only sailed into Progresso once but I have visited Merida several times. The market in the square on Sunday is not to be missed. Not at all touristy and very authentically Mexican.