Also, the bus is free and it takes about 15-20min to get to Playacar. They also go to Beach Palace and some other resort I cant remember. If you want to go to Cozumel, there are 2 different ferry companies. I think it was about $6 or so one way. DONT BUY A R/T TICKET! Buy a one way ticket because you wont know which ferry will be taking you back to the mainland. If you buy a R/T ticket with one company, you will have to take that same ferry back and they dont run that often going back to the mainland. I think there is a ferry every hour or every 2 hours going back.
Cozumel Palace is very small also. They dont have a beach, but they are located on the ocean and you can snorkel off the docks they have.