Cave vs. Cavern Diving: Everything you Need to Know

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Beware: You should never explore wild caves alone or without proper gear. Consider getting in touch with a Grotto of the National Speleological Society at or a qualified cave club. These groups are skilled and will train you. Without sufficient knowledge, preparation, and equipment, cave exploring can lead to serious injury or death.

If you are a passionate caver and love to explore the most unique places on Earth, it could be time to test your skills in Cave Diving. The thrill and challenge of an untouched underwater environment will satisfy your adventurous soul and always open the door to a new world.

Cave diving is about underwater exploration, traversing water-filled caves either for adventure or scientific research. You don’t have direct vertical access to the open air, light, or surface, which makes it extremely dangerous compared to traditional spelunking. For that reason, we can’t recommende it for beginners.

If you are a beginner, however, you’re in the right place. While cave diving requires professional diving skills, certifications, and equipment, you can learn all about it here before you get into the water.

What Exactly is Cave Diving?

Cave diving is a type of technical diving in which specially trained divers explore underwater caves. This extreme sport is considered one of the most challenging and potentially dangerous forms of diving or caving. Hazards include low visibility, strong water currents, tight passages, and the possibility of getting lost.

Divers venture into these subterranean environments to investigate their geological formations, study unique aquatic life, or simply for the thrill of exploration. Cave divers often compare the sensation of floating underwater to that of being in outer space. Despite the risks, these divers are often rewarded with remarkable sights like hidden chambers filled with mysterious and often vibrant marine life.

While some consider this a sport, a lot of participants are scientists. To start, you need specialized equipment and training. No responsible guide or instructor will let you go cave diving without it.

You’ll have to learn how to use redundant air supplies, guide lines, and diving lights, as well as demonstrate a strong understanding of diving physics and emergency procedures. If this is something that tickles your fancy, the payoff is certainly worth it.

What Distinguishes Cavern Diving From Cave Diving?

You might be thinking, “cavern is just another word for cave, so cavern diving must be the same as cave diving, right?” Not quite.

A cave is a general term for any natural opening in the ground, which extends beyond the zone of light and is large enough to permit entry of a person. If you find a hole somewhere, and you can go inside and escape the light, you’ve found a cave. Naturally, caves vary in size and structure, but they are commonly formed by erosion due to water on rock.

A cavern, on the other hand, is a specific type of cave. These are usually much larger and often created in soluble rock, like limestone. Caverns typically have more complex and intricate formations due to long-term erosion. Most consist of a network of connected, subterranean rooms or chambers, and feature stunning formations such as stalactites, stalagmites, and other speleothems.

So what about underwater? While both cave diving and cavern diving involve exploring underwater caves, cavern divers do not venture too far into the caves. They stop no further than 200 feet (60 m) from the surface, often much less than that.

Cave divers, on the other hand, explore fully submerged caves and often at significant depths. This is far more professional, difficult, and dangerous. Cavern divers stay within the sight of the entrance, while cave divers may find themselves in complete darkness as they go further into the chambers of the underwater caves.

This difference is paramount. The key thing to remember is that cavern divers must maintain a line of sight with the exit of the cave, regardless of whether they’ve reached the maximum distance or not.

Cave divers have depth limitations of 100 feet and distance limitations of 200 feet from an exit to open water. Irrespective of these measurements, individuals must maintain a direct line of sight to the exit, ensuring that light is always visible.

Graphic showing the difference between open water diving, cavern diving, and cave diving.
Two cavern divers swim through a bright blue underwater cave.

Which Caves Are Accessible for Divers?

There are several types of underwater caves that you can visit, once you’re qualified. Inland caves are created by dissolving limestone, dolomite, or gypsum rocks upon contact with mildly acidic water. Sea caves, on the other hand, are formed by mechanical erosion resulting from waves crashing directly onto rocky cliffs.

Zones of weakness can collapse, shaping and forming the cave. Occasionally, the process can result in the formation of an opening or aperture, enabling the release of pressure from each wave in the form of a spray jet.

Here is a concise compilation of cave systems that are available for exploration by divers.

Coral Caves

Coral caves are created through the growth of corals, which eventually merge to create enclosed caverns. The tunnels provide habitats for various marine species, including fish and sharks.

In addition to exploring natural wonders, intriguing discoveries have been made. For instance, during the early 2000s, a previously unknown species of coral was found attached to the ceilings of underground caves in the Coral Triangle. This coral species is unique due to its absence of symbiotic algae, which are typically essential for the well-being of most corals.

Solution Caves

Solution caves, called karst caves, can develop in various rock types, such as limestone, chalk, dolomite, and marble. The bedrock is dissolved by naturally occurring acidic groundwater entering the cave through bedding planes and other openings, forming the cave’s structure.

These cave formations are present in Florida, the Yucatan Peninsula in Mexico, and various locations in the Caribbean region.

Littoral (Sea) Caves

Littoral caves, or sea caves, form due to wave action impacting rock cliffs, and are present on coastlines worldwide. Sea caves form when the host rock contains a weak zone regardless of its type (sedimentary, metamorphic, or igneous). Mechanical erosion continuously impacts the formation and growth of the cave.

Prominent littoral caves, such as Fingal’s Cave in Staffa, Scotland; Neptune’s Grotto in Alghero, Italy; and the Apostle Island Sea Caves in Wisconsin, often exhibit chamber-like characteristics. Littoral caves of notable prominence are present in the Great Lakes, the New England coastline, the Sea of Cortez, and the California coastline.

Lava Tubes

Lava tubes form due to volcanic processes. When volcanic lava comes into contact with the sea, the outer layer of the lava rapidly cools and solidifies while the inner molten core continues to flow. This process results in the formation of a lava tube. This cave is prevalent in Hawaii and the Northwest Pacific coast.

Glacier Caves

These are formed within ice and are shaped by meltwater. While most common in glaciers, these can sometimes be found underwater, especially in polar regions.

Anchialine Caves

These are coastal caves formed in limestone or volcanic rock that are flooded with seawater and can have a freshwater layer on top due to the inflow from the land. Anchialine caves are unique in being influenced by marine, freshwater, and terrestrial conditions.

You can find some of the most unique and endemic species in these caves. An example of such caves can be found in the Yucatan Peninsula, Mexico.

What to Expect when you go Cave Diving

Cave diving combines the pleasurable aspects of scuba diving with an enhanced sense of excitement and adventure. Cave diving involves submerging into a confined cave environment without surface access and typically lacking illumination.

This adventure is notably challenging and ranks among the most difficult experiences in scuba diving. Being confined without surface access implies a lack of immediate means to reach the surface if necessary.

Cave diving provides an outstanding opportunity to engage in adventurous exploration and discovery. Due to limited light and oxygen availability, these environments support abundant but often unseen biodiversity. Caves contain unique rock formations, captivating scenery, and enigmatic regions yet to be explored.

Certifications and Skills

In case you are thinking about what certifications or skills you need to become a good & professional cave diver, there are a few things to consider.

  • First, you need to take the Advanced Open Water Diver course, which improves your underwater knowledge and skill. In order to participate in this course, you have to be at least 15 years old. It consists of almost 5 different adventure dives. Fortunately, it is a short course and can be done in 3-5 days. It teaches you how to dive to 130 feet.
  • After completing the Advanced Open Water Diving course, you go for the Cavern Diving Certificate. This special course is a tad tougher, in which you experience overhead environments and low-light conditions. They also teach you regarding the equipment which is used in cavern diving. For instance, you learn about gas management concepts and team skills for safely conducting cavern dives. You have to be 18 years old to enroll in this program.
  • Lastly, there is a complete Night Diving Course. Here you learn things such as standard cave diving policies, communication through hands and lights, different swimming techniques for different times inside the water-filled caves, the right usage of the equipment, breathing techniques, emergency procedures, and so on.
Two cavers on a night diving expedition, shining light with their flashlights ahead.
Dan’s Cave on Abaco Island, Bahamas.

Cavern Diving Courses

Before engaging in underwater cave diving, individuals must undergo rigorous training. Strict adherence to safety protocols is essential, even with proper training and certification.

Only individuals who possess the necessary qualifications and exhibit courage can access an unseen realm beneath the earth’s surface.

Cavern diving courses familiarize students with overhead cavern environments, including caves exposed to direct sunlight. Divers engage in skill development activities such as navigation, gas management, and contingency planning.

Additionally, you will learn about the concepts of “time stress” and “distance stress,” emphasizing the need to address any encountered issues promptly.

Graduates of introductory cavern dive programs are qualified to explore cavern-like environments at depths of up to 40 meters, with a maximum penetration distance of 300 meters into the cavern.

Novice individuals seeking reliable cavern diving courses may want to explore PADI’s Cavern Diving specialty course and SSI’s Cavern Diving course.

Cave Diving Courses

Individuals interested in further exploring extensive cave systems can enroll in a cave diving course. This course highlights the significance of teamwork in promoting safety.

This course builds upon fundamental in-water skills, management techniques, and lessons on team dynamics acquired in previous cavern diving courses. Students’ technical diving abilities are developed to equip them to explore more extensive cave systems. Divers will utilize additional equipment, including running lines and reels.

Moreover, it enhances physical and mental stamina, enabling divers to respond promptly to unforeseen circumstances and effectively execute self or buddy rescue operations.

Several cave diving locations charge an admission fee, and it is better to start with them. These have proper guidance and professional divers who can protect you in emergency situations. In addition, they can tell you about tips or important details regarding the dangerous spots of the cave.

Luckily, most cave diving spots don’t require any kind of certification. Cave diving experts choose them over known places as they are unique and nobody monitors what they are doing. Often people who come with a team and have full equipment will also have their own plans and methods for exploration.

Dive Right In Scuba

Some Locations for Cave Diving

There are many great destinations for cave diving. We have some of the most beautiful ones listed here below.

Grotta Azzurra: This sea cave is on the coast of island Capri. It is 60 meters long and 25 meters wide, and it is illuminated by the otherworldly blue light.

Blue Grotto, a radiant cave with bright blue water located off the coast of Southern Italy.
Blue Grotto is a nature’s marvel situated on the stunning island of Capri off the coast of southern Italy.

Chandelier Cave: The Chandelier Cave is in Palau. The amazing stalactites of the chandelier cave have grown into magnificent formations that look like chandeliers.

A diver in Chandelier Cave, in Palau.
Chandelier cave, Palau

Kuredu Caves: The Kuredu Caves are paradise for cave diving experts and scuba divers. You will find a whole host of aquatic animals here, unlike anything almost anywhere else on Earth.

Two divers encounter a huge turtle in the Kuredu Caves.
If you’re lucky, you might even make some friends during your time underwater.

Check out our list of the most famous underwater caves for even more options for your next underwater caving adventure.

Cave Diving Etiquette

Although there aren’t any specific laws and regulations regarding what you can do on a cave dive, the only thing which is most recommended by the experts is not to disturb the environment. This is good etiquette and shows that you respect the hobby and others who share your passion.

People do cave diving to explore the hidden world, not to disturb it or spoil the experience for anyone who may wish to try after them.

If you see any fossil or plant that is unique, don’t try to touch or remove it. If you’d like, you can report it to the museum, university, or some authority; it is their duty to preserve it and study it professionally.

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