Playa Mia is not in Playa Del Carmen, it's a short ways down from the pier in Cozumel. If you don't book the ship's excursion, it will cost you $14 (that's the price to most beaches in Cozumel) by taxi to get there and another $12 per person to get in. This includes the use of a beach chair, the freshwater pool, non-motorized beach toys, showers, bathrooms, snorkel euipment and the zoo. They have a little man-made underground mayan village you can snorkel through. You can also upgrade your admission to include the buffet, bar drinks and motorized beach toys. If you want to go to Playa Mia, it might be more cost effective to take a taxi and pay the admission price rather than book it through the cruise line. Otherwise, there are a lot of other free beaches on Cozumel that offer the same hospitality, without the cost.