It was really too hot to enjoy the time here, but the island is beautiful. It's the cruise line's private island. The staff works extremely hard here because they have to serve the guests from the ship here, clean it up, get back to the ship just to serve you again. The staff works extremely hard on this ship when they stop here.
There is plenty to do but I caution you that it is expensive to do things on the island.
It's a beautiful island. If you get a chance to do a tour, don't forget to try the banana bread and coffee. It was simply delightful. Caution: The locals are brutal with the sales. EVERYONE tries to sell you something. Do not take anything that you aren't willing to buy.
This is my second time at Cozumel, and I have the same experience. Will not get off the ship at Cozumel again. The locals here are worst than any port I've been on. If you don't want to purchase anything, just tell them you're broke. They'll leave you alone.