I was really worried when I found out we were going to Costa Maya instead of Cozumel because I love Cozumel...but we just got back and Costa Maya was pretty cool. There was a nice little beach right close to the dock that was for anyone to sunbathe ( I dont know about swimming but some people were..it was kind of rocky) but there were nice shops...though more expensive than cozumel. If you do go there is a pool in the middle of town with a swim-up bar if you want to take the risk of swimming in who knows what kind of water, but it was very cool looking. Also, a must when you go is to visit Mamasita's and try the nachos with chicken!! The best I have ever had!!!!!
Edit: Moved to Caribbean Port Chat. RF