How Dangerous Is Cave Diving? Read This Before You Go!

Cave diving isn’t for the faint of heart. Unlike open waters, cave diving involves narrow spaces, poor visibility, unpredictable current, and a slew of other hazards. This is the reason why cave diving is considered a technical dive and those who want to brave this adventure must secure the necessary license. Still, many beginner divers wonder, how dangerous is cave diving in real life?

This quote from RAID technical diver Chris Haslam will answer the question:

“If someone questions the dangers of cave diving, they’re fully unprepared to meet the challenge.”

Divers who prematurely want to jump into cave diving should learn from the lessons of the Tham Luang Cave Rescue. Back in June 2018, 12 boys got trapped inside the cave as rains increased the water level, blocking the main entryway.

All the 12 boys emerged safe two weeks later. However, the successful rescue cost the lives of two veteran divers. This incident highlights the dangers of cave diving and something every diver should learn from.

What is Cave Diving?

how dangerous is cave diving

Cave diving is a combination of both scuba diving and spelunking. Divers will literally explore underwater caves, cenotes, and similar topography.

Since many underwater caves are hard to access, it becomes a home to unusual marine life. This lures many divers to brave the complicated dive. In fact, cave divers often discover new bacteria and marine species during these dives since underwater caves are teeming with life.

Due to the hazardous nature of cave diving, a person needs a cave diving license to be allowed to go on this adventure.

Moreover, cave diving is a type of penetration diving. This means that the divers can’t swim vertically due to the cramped spaces of the caves. In some cases, divers would have to swim in reverse to get out of a tiny space.

Aside from that, cave divers have to be fully prepared for any gear malfunction or accidents that may occur while inside the cave. From busted dive lights, problematic air supply, and emergency rescue – cave divers must be prepared for such scenarios.

To give you a better picture of how intensive cave diving training is, most divers will train while blindfolded. This is to simulate potential emergencies like poor visibility.

The Dangers of Cave Diving

By the name itself, you can easily tell right away that cave diving is serious business. Most importantly, this adventure is associated with the following hazards:

🤿Running out of air

how dangerous is cave diving

The main danger of cave diving is the risk of running out of air. Unlike diving in open water, divers can’t ascend immediately when their air runs out. Worse, the maze-like paths in caves will take divers longer to get out, thus more air consumption.

For a diver, running out of air is one of the most dangerous scenarios. It can easily lead to death, especially if there’s no buddy to share air with.

🤿Getting lost

Underwater caves can have branching cenotes, where divers can get lost without proper planning. When divers fail to find their exit point, they will be stuck in the cave until their air runs out.

And when a diver’s air supply runs out, death will be imminent. Some divers can find an air pocket in the cave, but it’s also a matter of time until the natural oxygen runs out.

🤿Buddy separation

Another danger of cave diving is getting separated from your diving buddy. This can happen due to various reasons, including poor communication, sudden changes in current, and poor planning.

Buddy separation is dangerous because you don’t have anyone to ask for help in case of equipment malfunction. Also, searching for a lost buddy inside a complex underwater cave will expose the diver to a higher risk of accidents, including low air supply.

🤿Equipment malfunction

Before a dive, divers have to check their equipment intensively. Buddies also perform a quick check of each other’s equipment to ensure that everything is all set.

Equipment malfunction is a catastrophic scenario, which can be prevented with proper inspection and preparation. Still, cave divers are trained to handle such malfunctions.

🤿Loss of visibility

One of the biggest enemies of cave divers is the loss of visibility. Underwater caves are often pitch-dark, and without a dive light, a diver can easily lose track of his path.

Aside from that, erosion can occur inside the cave. The divers’ fins will also disturb the dirt on the cave floor, making the water murky. When this happens, the diver won’t be able to see his buddy, which can take a life-threatening turn if accompanied by an equipment malfunction.

🤿Cave collapse or falling debris

Since underwater caves aren’t easily accessible, it will be hard for divers to assess the structural integrity of the walls and ceilings. There’s a risk of collapse in case the diver pushes or disturbs the area. When this happens, the entrance of the cave will be blocked and the diver will be trapped inside.

In worst-case scenarios, the cave will collapse and bury the diver alive.


The combination of primary lines and jump lines in cave diving creates a risk of entanglement. Being tangled can trap the diver inside the case until his or her air runs out.

Also, the lines can get stuck on sharp rock formations inside the cave. While it’s likely that the lines will break, it will take the diver a lot of effort to unravel the lines and swim back to safety.

🤿Flow reversal

Flow reversal happens in some cave systems. This is when the water flow changes directions abruptly. This can block the diver’s exit and entrance point. Also, flow reversal can make it hard for divers to get out, thus consuming more air in the process.

Moreover, flow reversals can happen due to heavy rains, increasing tides, or a sudden gush of water from the opposite direction.

🤿Toxic gas

Since underwater caves are often undisturbed, there can be toxic gas formation in some instances. This is why cave divers never assume that an air pocket has breathable safe.

In fact, these air pockets might be packed with toxic gasses that can knock a diver unconscious. When this happens, drowning may occur.


Due to the lack of sunlight, underwater caves tend to have colder water than the open sea. This is why hypothermia is a serious concern, especially if the dive is happening on a cold day.

Safety Precautions When Cave Diving

Even if you secured a cave diving license, it’s still important to keep precautionary measures in mind. The following are some of the important safety steps you should always practice when going for a cave dive:

🌊Never go cave diving alone

Going on a cave dive alone is a suicide mission. If you got lost or experience an emergency, no one will be there to help and save you. In the end, your adventurous dive can turn into a search and rescue mission for the coast guard.

If you’re planning to cave dive, always coordinate with a local dive center. You should also team up with a trained cave diver to serve as your buddy.

🌊Manage your air supply

The golden rule in cave diving is that you should reserve two-thirds of your air supply for our ascent or return. You should calculate this even before you hop into the water. This will save divers from the risk of running out of air.

Aside from that, you should know what to do in case your air equipment malfunctions. This is why cave diving buddies are trained to perform air sharing when this problem occurs.

🌊Carry multiple lights

Underwater caves are often beyond the reach of sunlight. So even if you’re diving on a hot summer day, the cave can be pitch dark. This is why you should carry at least three dive lights before you descend.

It’s better to have spare lights than to be left in the dark underwater and without a plan. No matter how heavy-duty your light is, you should never take chances without a spare.

🌊Prepare for the dive mentally

Aside from the technical training and physical preparation, you should also condition your mind for the dive.

Cave diving can be a scary and challenging experience. It’s important that you’re mentally prepared for the worst-case scenario. This will prevent panicking, which can lead to more problems underwater.

🌊Stay within your training

When it comes to diving, there’s a golden rule you should respect: always stay within your level of training. This applies to all types of dives, but most critically for cave divers.

Going beyond your training level will put you in harm’s way. For example, entering a complex cave that’s not part of your training will increase your risk of being trapped, running out of air, or being lost.

🌊Mind your depth

It’s easy to lose track of your depth when exploring a cave. This increases the risk of decompression sickness among divers.

Always check your dive computer to ensure that you’re not going deeper than what you intended. You should also watch out for your buddy’s depth to ensure that both of you are within the safe range.

🌊Adjust your movement techniques

how dangerous is cave diving

Silt-outs are a major problem among cave divers. It affects visibility, which also increases the risk of accidents among divers.

To prevent disturbing the silt on the underwater cave, you should adjust your finning techniques. Aside from silt-outs, the right finning technique will let you move around narrow spaces easily.

Overall, you should learn the pull and glide technique, where you cling to crevices and rocks to pull yourself forward. This will prevent your fins from scraping the silt.

🌊Practice your posture

Unlike open water diving, cave diving requires a different posture. This is to allow the diver to move around without disturbing the silt with their fins.

Cave divers often swim with their faces down and knees bent. Their fins are elevated from their body to propel them while avoiding the silt at the same time.

🌊Dress for the part

Cave divers often wear full scuba suits that are rated for cold temperatures. Since underwater caves are rarely reached by sunlight, the water inside can be extremely cold. Without the proper suit, a diver may succumb to hypothermia. Aside from that, you should wear diving boots to protect your feet from the cold.

Your choice of a diving mask is also crucial for your safety while cave diving. You’d want to use a mask with a low-profile design so it doesn’t consume too much space in front of your face. Aside from that, you should choose a mask with a black frame so it doesn’t absorb light that may distract the eyes of other divers.

How to Get Certified For Cave Diving

PADI offers a specialty cavern diver course, which you can avail of it in your local PADI diving center. However, you need a PADI Advanced Open Water license for you to be eligible for this course.

Aside from the license, cave diving requires intensive training. Also, only 18-year-olds and above are allowed to enroll in the course. And since cave diving requires firsthand experience, not all PADI centers can offer this training. Most often, it would be available in diving centers located near underwater caves.

Also, you need to record at least 25 dives before you can enroll in a basic diver course. The number of dives varies depending on where you’re going to get the certification.

Overall, the diver needs to master twin-tank systems, use of jump lines, emergency rescue, and equipment malfunction solutions.

Cave divers are also trained to manage stress and panic. Above all, cave divers can’t be claustrophobic because underwater caves are extremely cramped and narrow.

In the end, the requirements for cave diving certification vary per diving center.

Top Cave Diving Spots You Should Visit

If you’re all set with a cave diving certification, proper equipment, and experience, you can brave these cave diving spots:

  • Indian Springs. Also known as the Sherlock Springs, this underwater cave in Florida is known as the best cave dive in all of North America. Its main passage tunnel has a depth of 600 feet that splits into upstream and downstream. It’s a technical dive that requires a full cave diver certification and proof for 100 cave dives.
  • Cenote Angelita. This wonder in Tulum, Mexico is 200 feet deep and most divers won’t dare reach the bottom. At the surface, Cenote Angelita is surrounded by a spectacular rock formation that mystifies many divers around the world. Unlike Indian Springs, this cave is easier to access and only requires an advanced open water certification.
  • Ben’s Cave. This cave dive site is located in Lucayan National Park in Grand Bahama. It’s a 6-mile freshwater cave and the longest of its kind in the entire world. It’s similar to Cenote Angelica that only requires an open water diver certification.
  • Eagle’s Nest. Eagle’s Nest is dubbed as the ‘Mt. Everest’ of cave diving. It has a maximum depth of 300 feet and goes down a narrow chimney-like passage. However, you should know that Eagle’s Nest has claimed many lives before due to poor visibility, accidents, equipment failure, and divers overestimating their abilities.

Frequently Asked Questions

Q: Can cave diving be safe?

A: With proper training and certification, cave diving can be a safe and rewarding experience. However, you have to undergo and pass rigorous training to ensure your safety. This may include weeks of training and practice dives before you explore more complicated caves.

Q: How long can you cave dive for?

A: In general, cave diving lasts for an hour. However, the most trained and experienced divers can stretch this for up to 15 hours. Such a cave dive involves intensive planning, exquisite equipment, and years of experience.

Q: How deep can cave divers go?

A: Most beginner cave divers won’t go deeper than 30 meters. But for highly trained technical divers, the maximum depth can go as far as thousands of feet. Most of these dives are beyond the reach of sunlight and require special equipment.

Q: Is there air in underwater caves?

A: It’s possible to find underwater air pockets in caves. However, it’s not always safe to breathe as some caves can have toxic gasses in them. Divers need to study the elements in the cave before they try to use the air pockets as emergency air sources.

Q: How many cave divers are there in the world?

A: Professional cave divers are quite a rarity in the diving community. Some experts say that there are only less than a hundred highly trained cave divers in the world. This is due to the complexity of the dive and the training necessary to secure a license.

Final Words

How dangerous is cave diving, you ask? It’s probably one of the most challenging and demanding diving experiences you’ll ever have. It requires intensive training, preparation and planning to ensure the safety of divers.

Those who wish to go cave diving should never underestimate the hazard of this adventure. Always prepare and train before you even consider taking the plunge.