When you look at Costa Maya from the ship all you see is green. It was lovely. When you look at GC and Cozumel, you see stores and roads.
It was really easy to get on and off the ship. They had a trolley pulling people up and down the dock. There's a little shopping 'mall' with a resturant and a big pool. Most everybody is selling the same stuff. Make sure you decide on a price that you want to pay and 'negotiate'.
There was one man and two boys painting small tiles with their fingers. Lovely outdoor scenes. Make sure you find them. Also, there was a man making poster size pictures with spray paint. I felt very badly for the dressed up donkey waiting for someone to sit on him for a picture.
There's a beach with nice chairs and umbrellas. The coast line is very very very rocky. I was told later there was a no swimming sign but there were a lot of people in the water. I ran back to the ship for my snorkle gear. There's a pool on the beach too but it looked really scuzzy to me and I wasnt' getting in that.
There is a small town that you can take a taxi to. There is a taxi stand in this small shopping mall with all sorts of prices listed. Do some research.
The shopping only took an hour or two. Like I said, you'll see a lot of the same stuff over and over again. I think they were some shows going on but I missed them. After a few hours here, you might get a bit bored.