Mar Adentro Diving is an SSI and PADI dive center based at Blue Kay on the malecon of Mahahual, on Mexico's Costa Maya, giving divers direct access to the Mesoamerican Reef, the second largest coral reef system in the world. The center runs trips to Banco Chinchorro, a huge coral atoll and biosphere reserve, as well as Xcalak's reefs, night dives, deep dives and a lionfish safari. Beginners can start with a Discover Scuba Diving experience before progressing through a full range of SSI/PADI courses: Open Water Diver, Advanced Open Water, Rescue Diver, Emergency First Response and specialties such as deep diving, working toward Divemaster. Instructors keep a personalized pace, typically around three days per certification course, and courses include study materials, instruction, equipment and certification fees. Guests can expect to see colorful reef fish, turtles, rays and, with luck, manatees while diving the clear waters of the Costa Maya with this small, locally based team.