I believe the shuttle is $4 round trip per person. If you don’t want to take the shuttle, the Malecon (boardwalk kinda) is a short walk with shops, restaurants, statues, and boats.
everything should be open on thanksgiving.
Costa Maya go to the ruins or The Crazy Lobster
Belize: the ruins, snorkeling, or cave tubing (we used butts up)
Cozumel : wait for it…. The ruins (very culturally important to the Mayan people, just not that impressive to view). Go tequila tasting.
Costa Maya has a huge port area (many people spend the day there) with shops, bars, restaurants, and pools. But it’s cruise line built so don’t expect Mexico prices.
The ruins on Cozumel are physically unimpressive, however, culturally they are more important than most of the mainland ruins. Well worth the visit. Hire a driver for the day. We visited a tequila and a chocolate factory.