The Chicxulub (Chik-shu-lub) structure was formed 65 million years ago when a large celestial body -- a comet or an asteroid -- slammed into the Yucatan Peninsula with a force that makes a nuclear blast seem like a firecracker.

The collision gouged a crater nearly 8 miles deep (in comparison, Mount Everest is 5.5 miles high) and 125 miles in diameter and sent 12,000 cubic miles of rock, dirt and debr

is spinning into the earth's atmosphere. The material blocked the sun, causing extreme changes in the Earth's climate, which many scientists believe resulted in mass extinctions.

The ground surface in Yucatan is made of a thin limestone, which rain water easily filters through to form underground rivers. In some places, the ground above these rivers has weakened and collapsed over time. Locally, these openings are called cenotes, and are underwater cavern openings leading to the caves of the underground rivers. Cenotes are the doors to this amazing aquatic system.

Divers in caverns are always within sight of natural daylight. Every diver carries a diving light (provided without extra charge) to better see the cavern formations.

Because it is an "overhead environment" (partially enclosed), cavern diving must be organized and supervised by a Full Cave Diver, who is, at Poseidon Dive Center, also a certified Cavern Instructor.

Cenote Cavern Diving is an amazing experience, and you won't find better cavern dives anywhere else in the world!

This 1 day tour includes: Ground transportation from Merida to the cenote, scuba diving gear, 1-2 tanks, diving light, snacks and soft drinks.

RECOMMENDED FOR: Those in good physical condition. You must be a certified diver and show proof of certification in order to participate in scuba diving activities.

NOT RECOMMENDED FOR: Pregnant women, children under 10, adults weighing more than 250 lbs. or those with a heart condition are not advised to participate in these activities.

What to bring:

Swimsuit, Towel, Sunscreen, Mosquito repellent, Waterproof Camera.