Cozmel, Belize, Honduras, and Grand Cayma
I wouldn't go on that cruise... Belize and Honduras are some of the poorest countries in the western hemisphere..
On top of that because of the huge disparity between the wealthy and the poor, crime is high.
If you are going to go out, take a bare amount of money and wear really raggy clothes. My friend got robbed twice in one day...
I would def do an eastern caribbean cruise route.
I also used to work on cruise ships, are you sure you want to do this? It's restricting and I assume you're going on the big liners.. so your 2,999 other (obnoxious) friends are getting off the boat with you ruining any chance you get an authentic experience of these ports.
In places as lovely as Honduras, you're going to get off and have a really nice fence separating the locals from the merchants that are going to inundate you with shit to buy.
Over all, you're going to have a much better experience planning your vacation around one island. I recommend Curacao.. I had a great time.