The oldest dive operation in Akumal, on the bay itself a hundred kilometres south of Cancún, open every day from eight until five.
Akumal means "place of turtles" in Maya and the name is not decorative: green turtles graze the seagrass in the bay all year. Since 2016 the bay has been a federal refuge — you may only enter the protected zone with a licensed guide, in a life jacket, six swimmers per guide, forty-five minutes, no touching and no sunscreen. Fines for going in alone are real.
Beyond the turtles they run the reef, the cenotes inland and the Yal-Ku lagoon at the north end of the bay where fresh water meets salt.