Mexico’s Yucatan Peninsula is well-known among the cave diving community for its seemingly endless maze of underground, water-filled caves. The extensive network of caves hide untold underwater secrets, including beautiful stalactites and stalagmites, fossils, and artifacts from the distant past. It’s been said that here, time stands still.

While most of the caves are yet to be explored, the known systems stretch for literally hundreds of miles under the surface of the Yucatan Peninsula, and it’s believed that the region hosts the largest and longest cave system in the world. For divers they hold untold dangers, from tight squeezes to maze-like passageways, and exploring them requires highly specialized training and equipment, much of which has only been recently developed. Diving in the maze of underground passageways can be very dangerous, and people die periodically – often because they do it without proper training or equipment.

One of the teams who actively explores the underground cave systems is the ATI Cave Exploration Team, led by Ivo Kalushev. Ivo is the former owner of the Roke Speleology school in Europe and has 25 years of cave exploration and teaching experience as a Technical Speleology and Emergency Rescue Instructor Trainer. Ivo is the leader of the ATI Cave Exploration Team and he currently teaches specialized exploration-specific courses to certified cave divers– and explores the caves himself. He’s also the subject of the new documentary movie “The Unexplored” that takes viewers along with him as he explores deep into the caves of the Yucatan, using technique known as ‘no-mount’ exploration cave diving.

Ivo prepared his gear for a trip underground.

Ivo prepared his gear for a trip underground.

The film was shot over a period of one year in the underwater caves of the Riviera Maya and features some extreme cave diving exploration and stunning imagery. It provides a firsthand look at the beauty of the underwater caves as well as the specialized techniques used to explore them, following Ivo and his dive team on an exploration deep into one system where he needs to remove all of his gear – including his fins and weights – to fit through a narrow restriction.

“Our goal is to share with fellow divers and the larger public the beauty of these submerged caves as well as the knowledge and attitude required when approaching an activity as risky as cave diving”, says Peter Kolev, a member of of the ATI Cave Exploration Team.

Peter contacted us at, and we’re pleased to share “The Unexplored” with you on the first day of its release. The movie is about 38 minutes long, and definitely deserves the time to watch it in its entirety. Please set aside some time to watch this beautiful and inspirational movie on diving the underwater caves and learn more about the divers who have dedicated their lives to exploring them.

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