I don't know a lot about it but the idea of getting to see pink flamigos and other birds excites us. We are bird watchers here at home and love nature. Here is the link to it I don't see where carnival offers the same tour. www.autoprogreso.com/trips.html.htm
From what I've read it's only a 2 to 3 hour tour which is plenty long enough for us since it's not a carnival tour. LOL don't want to be left behind. We are also thinking of doing the $2 bus tour of the city I read it's only about 20 minutes long. That should leave us plenty of time for a little shopping.
We can't figure out what to do in Cozumel. Thinking of doing the Chankanaab tour there, but don't know for sure yet.