Cenote Cavern Diving Rules

Cenotes are unique and fragile ecosystems that support numerous life forms, including mammals, birds, reptiles, insects, and various plants. It is our duty to help protect and preserve these unique environments. Avoid using sunscreen and repellents, even “biodegradable” ones. Cave formations, unlike reef coral formations, are not self-rejuvenating. Once damaged or broken, they are lost forever. Leave the cenote as you found it or better. Take only memories with you, kill only time, and leave nothing but bubbles.

The following rules are for your safety and for the preservation of cenotes.

General Limits of Diving in Cenotes:

  • Always within the daylight zone

  • 60 meters/200 feet maximum distance from the nearest surface point

  • All dives will be no-decompression dives & within recreational limits

  • Limited to within the cavern zone, never beyond cave entrance signs

  • Always above and within arm’s reach of the cavern line

  • No passing through restrictions smaller than where 2 divers shoulder to shoulder can comfortably pass

  • Exiting groups have the right of way over entering groups

4 divers per guide; no solo diving. Divers must be in a single file line, 2m/6ft max distance apart.

No Knives, No Gloves, No Snorkels, No Danglies, No Touching, No Markings

All divers must follow the rule of 3rds. 1/3rd to enter, 1/3 to exit, 1/3 for reserve. Move your light up & down to gain the attention of your guide then shine your light on your hand to indicate 2 or 1 once you’ve used a third and the second third of your gas.

No pony bottles allowed. Divers may use sidemount or doubles configuration if certified.

Hand Signals (Left to Right, Top to Bottom):

2000 PSI/140 Bar, 1000 PSI/70 Bar, Okay, Out-of-Air

Golden Rule: any diver can end the dive at any time by giving the thumbs up signal, Stop, Something’s Wrong, Descend

Come Closer, Descend Lower, Ascend Higher, Watch Your Trim

Your dive light must be on at all times; you might be asked to cover your light with your hand to enjoy the natural light. Never shine your light on another diver’s face. Move your light up/down to get the attention of your guide for a non-emergency. Move your light rapidly side to side for an emergency. Move your light in a circle to signal that you’re okay.

Stay above the cavern line, never below to avoid entanglement. Always remain within arm’s reach of the line except when surfacing in air domes at Dos Ojos, Dreamgate, or Tak Be Luum, or when there is no line, like at El Pit, Yaakun, Angelita, Zapote, Kin-Ha & 7 Bocas. Never pull on the cavern line.

Have good buoyancy control and stay in trim. Frog kicking is preferred; flutter kicking can lift up a lot of silt if you’re not careful.

Divers should be aware that the profile of most cenotes requires more frequent adjustments to their BCD. Anticipation is key.

Your buoyancy changes when diving through halocline. Divers should vent their BCD to descend through the halocline and add air to your BCD to become neutral above the halocline.

Classification of Cenotes