Cozumel has a ton of options, the majority of things only being a $5.00 taxi ride away.
-Golf -Parasailing -Snorkeling/Diving
-Shopping -Jet Skiing -Surfing
-Windsurfing -Car Rentals -Tequila Tours
-Mayan Ruins
The general amount of these can be located in the main square once you step off the ferry.