Area has been well thought out with added things like a long zip line and a small roller-coaster. Charges for these things are a bit high, though. Lots of beach-oriented tours should please any beach-loving cruiser.
Jamaica features high-pressure people trying to sell their goods, an abundance of pick-pockets, and too much marijuana for me. But it is still a beautiful island, and Dunns River Falls is the standard tourist site for novice cruisers - you climb the falls on slippery rocks, holding hands. It is fun, and everyone should do it - once. But watch your belongings - they can disappear in an instant.
Cozumel has become the typical tourist port, so expect lots of merchandise for sale and the prices can be good - or bad - you have to watch what you are doing to make a good deal. It is no longer the home of local merchants selling things they made - it is the home of merchants selling things made in China that look Mexican. If you go off the main streets, though, there are some interesting shops, but it is wise to be careful and be safe. Cozumel is not basically a dangerous port, but the economic conditions everywhere are not what they once were, and it is simply wise to be safe.