In the unlikely event that the sea is too rough to dive Xcalak, dive centers offer a two tank trips to Cenote Azul and Bacalar, the Lake of Seven Colors.
Cenote Azul is the largest pit cenote in Mexico, 600 feet across and 290+ feet at the center. The diving here is the most bizarre and thrilling fresh water dive you will ever experience. The geological formations look more like a moon-scape with submerged trees populated by schools of live bearing, fresh water fish. At 100+ feet, you can look up and see swimmers above but not the bottom.
The water in this cenote is much warmer than what you will commonly experience in the smaller cenotes, with an average year round temperature above 80° F. Visibility is 30 to 50 feet.