Cavern Diving: An Essential Guide for Beginners

Cavern Diving at Cenote Chac Mool - Photo by Ruta de Cenotes at Ruta de Cenotes

Cavern Diving: An Essential Guide for Beginners

A subject that sometimes sparks debate on a dive boat is whether a dive site counts as a cave dive or a cavern dive. If you’re out on a recreational dive boat, the chances are it was a cavern dive. When it comes to scuba diving, there is a subtle distinction between a cave and cavern. Cavern and cave diving differ in terms of how far from the entrance a diver goes, with cavern divers always being able to see the entrance or exit. However, whether you are considering entering a cavern or cave, you should be aware of the potential risks involved with diving in an overhead environment and be suitably qualified and equipped for the dive.

We’re going to take a deep dive into the basics of cavern diving to give you an idea of the differences with cave diving, the potential hazards involved, and where to go should you wish to tour underwater caverns on your next dive trip.

What Is Cavern Diving?

The main thing that defines a cavern is whether or not a diver can see natural light streaming in from the entrance when inside. While a cave diver will penetrate further into a cave system than the natural light, a diver exploring a cavern will stay where they can still see the light and the exit.

When cavern diving, however, there are more inherent risks than when diving in open water. Different types of diving present different kinds of risks, and divers must be aware of them. To ensure you have the skills to explore caverns safely and to reduce the risk, recreational divers should enroll in an appropriate training course with a suitably qualified cavern diving instructor.

Both cavern and full cave divers need proper diver training and diving experience before venturing into underwater caves or caverns. Various training agencies certify divers in both disciplines and have instructors who specialize in this type of penetration diving.

What Is The Difference Between Cavern Diving And Cave Diving?

Cavern Diving at Cenote Chac Mool - Photo by Ruta de Cenotes at Ruta de Cenotes
Cenote Chac Mool – Photo by Ruta de Cenotes at Ruta de Cenotes

Cave diving involves exploring submerged underground cave systems and passageways, which are typically completely dark and can also be tight and narrow. When cave diving, you are in an unforgiving, overhead environment, and you don’t have direct access to the surface due to the cave’s ceiling blocking the way. You will also not have sight of the exit as you push deeper into the cave. The typical cave diving environment can be challenging due to the tight spaces, the need for excellent buoyancy control to avoid stirring up silt, and the need to carry extra equipment.

Cavern diving can be seen as an introduction to cave diving, as there is some cross-over in the skills required. However, when cavern diving, you only enter the cave a short distance, staying within the light zone for an easy exit to open water. Cavern diving allows you to enter overhead environments within certain parameters, with more limits to restrict a diver’s penetration until they are ready to take the next step and become a full cave diver.

Is Any Special Certification Or Training Required For Cavern Diving?

To be able to minimize risks when diving caverns, a cavern diver course is required. Taking a course from a qualified instructor gives you the knowledge and skills to explore caverns correctly, allows you to plan your cavern dives properly, and will also cover the specialized equipment needed for cavern diving, disorientation and anti-silting techniques, and allow for safe practise of the new skills in a safe environment.

Dive planning for overhead environments is a little more complex than open-water dive planning, and you will also learn about the depth and distance limits when entering a cavern, air management for cavern diving, and the limits of this type of diving.

Cavern Diving Limits

When diving in open water, divers also have limits to their dives, but when cavern diving there are more limits to be aware of in order to keep yourself safe. Diving in an environment without direct access to the surface means extra precautions need to be made. During a cavern diving course, you will learn about these limitations and why they are important.

To earn a certification in cavern diving, you will have to show awareness of these new limits and the ability to stick within their restrictions. Cavern diving limits typically include:

  • Staying within the daylight zone, i.e. within sight of natural light from the cavern’s entrance.
  • The rule of thirds, i.e. penetration is limited to 1/3 of a single diving cylinder
  • You must remain within a certain linear distance from the surface, e.g. the combination of depth and horizontal penetration must not exceed 200 linear feet from the surface
  • Maintain a maximum depth of 130 ft/40 m.
  • Stay within no-decompression diving limits

Cavern Diving Equipment

divers exploring a cave underwater
Photo by Francisco Davids on

Diving inside caves and caverns requires the use of specialized equipment, and on the cavern diver course, you will be introduced to some new equipment as well as some different equipment configuration ideas. When inside an overhead environment, there are more chances to snag your equipment, so special emphasis should be placed on fine-tuning buoyancy and trim as well as how to configure your equipment to reduce the risk of entanglement.

You may also be introduced to a new piece of scuba gear. Cavern and cave divers need to lay a guide line when entering overhead environments. The main purpose of this is to enable you to easily find your way back out. There are special techniques for laying a line, and you will also learn about different types of reels and which ones are best for cavern diving.

During the course you will learn how to safely lay a line, and you should also practice doing this while also carrying a dive light. While cavern divers stay where they can see the light from the exit, there is reduced light inside a cavern, and you will also need to be able to use your dive light as a signalling device.

You will also work with your instructor to assure your buoyancy and trim levels are good enough for the cavern environment too. Poor buoyancy, carrying too much weight, and inadequate finning techniques lead to silt being disturbed and visibility reduced inside caverns, and you will work on improving these areas of your diving too.

Four Ways To Cavern Dive Safely

  1. Enroll in a cavern diving course. Ensure you learn the correct techniques from a qualified and reputable cavern diving instructor, and do not enter caverns without the proper training.
  2. Do not venture beyond the sunlight zone. Ensure you can always see the exit when diving inside a cavern.
  3. Dive only with a buddy who is suitably qualified. Do not encourage divers without the appropriate diving certification to dive beyond their personal limits.
  4. Limit your cavern diving to appropriate sites. Choose specific cavern sites.  Avoid sites that lead to narrow passageways lined with stalactites and stalagmites, and dangerous cave systems until you are qualified and experienced enough.

Best Cavern Dive Sites

Luckily, the world is blessed with plenty of caves and caverns to explore and many divers enjoy doing so on a regular basis. Here’s a few ideas of great locations to head to if you’re looking to explore the ocean’s darker corners:


The area surrounding the Gulf of Mexico has a great concentration of caves and caverns to explore, if suitably qualified. Famous cave diving locations include Ginny Springs, Devil’s Den, Paradise Spring, and Blue Grotto

Riviera Maya

Cenote Angelita - Photo by Paranamaya Blanco
Cenote Angelita – Photo by Paranamaya Blanco at

To many, the Yucatan Peninsula is a cave diver’s paradise.  Famed for the many cenotes – water-filled limestone sinkholes – there are plenty of options for both cavern and cave divers, with Tulum and Playa del Carmen being particular hotspots, and Cenote Angelita near Tulum a good starting point.


If you’re on a shark diving expedition to Palau, and fancy a change of scenery from the wall-to-wall sharks, then you could opt to complete your cavern course on dive sites such as Chandelier Cave and the Blue Holes.

The Bahamas

Also in the vicinity of the Gulf of Mexico, the Bahamas also has its fair share of caverns and caves. The islands’ unique limestone topography has led to the formation of the world’s largest collection of marine blue holes awaiting to be explored.

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