Playa Mia (formerly Playa Sol): Closest beach to Mariposa Estates. It has water sports, pier with dive boat pick up, large restaurant, bar, small zoo, swimming pool, watersports, several shops. There is an entry fee to get in but you can bypass that by using the public access adjacent to the Playa Mia access. They can charge you if you use any of their facilities/amenities (beach chairs, water sports, etc.), but otherwise you are free to use the beach.
San Francisco Beach: 1/2 mi. north of Mariposa Estates. It has a restaurant, bar, swimming pool, shops and watersports.
Paradise Beach: 3/8 mi. north of Mariposa Estates. Beautifully landscaped. It has a restaurant, several bars and water sports.
Palm Beach: 1/2 mi. north of Mariposa Estates. Palm Beach has a restaurant, bar and water sports.
Nachi Cocom: 3/4 mi. south of Mariposa Estates. Swimming pool, jacuzzis, restaurant, bar, pier for dive pickup and watersports.
Palancar: A couple of miles further south, this quiet beach area has a restaurant and bar.
And for a change of pace, you can head to the other side of the island where you'll find a bunch more!