The Devil's Throat at Punta Sur is an underwater cave formation located offshore of Cozumel that starts at approximately 80 feet of depth and opens up at approximately 135 feet - right at the edge of recreational dive limits.

The Devil's Throat is considered a "must dive" experience by scuba divers visiting Cozumel. Yet, due to the depth and the fact that it is a cave, it is considered an advanced dive. A longer than standard Safety Stop, or stops, is heavily recommended to minimize risk of decompression sickness. A dive computer is recommended for additional safety.

Diving the Devil's Throat requires use of an underwater light, and it is recommended that divers not scissor kick because it stirs up sediment which heavily obscures visibility.

(From Wikipedia.org)