Scuba diving is a pretty safe sport.

That being said, cave diving comes with heightened risk.

According to CaveDivers.com.au, 368 cave divers died between 1969 and 2007.

Cave diving is for the most adventurous of scuba divers. For those who are willing to push boundaries to the absolute limits.

It’s technical diving at its most technical.

When things get more technical, more accidents happen.

This type of diving combines the claustrophobic subterranean exhilaration of caving with perilous aquatic scuba diving.

It might be risky, but it exists for a reason. It’s exciting and exhilarating, and people love it.

So if you’re going to get involved, do it safely.

Below, we’ll tell you about five cave diving tragedies you should know about, as well as some tips on how to be safer on your cave dives.

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#1 – A recovery gone wrong

You might have read about Boesmansgat Cave AKA Bushman’s Hole if you’re a scuba diving fanatic.

It’s the deepest underwater cave in the world, found in South Africa, laying low at 271 meters.

You may have also heard about Dave Shaw.

He’s set world records, including deepest cave diving on a rebreather (equipment that lets you recycle air), in the cave that would later take his life.

During his first dive there, he came across the remains of Deon Dreyer, who was taken hostage by the cave in 1994.

He tried to recover the remains but it was impossible. He promised Dreyer’s dad he’d try again.

In January 2005, Shaw embarked on his promise. It took him a mere 10 minutes to drop 271 meters to the cave’s base.

In video footage taken by Shaw, it’s evident that Shaw joined Dreyer in a fatality just 25 minutes into the dive.

He filmed his own death…

Shaw went down first to send up the remains. Shirley, his dive buddy, dropped shortly after, but there was no sign of Shaw. He dropped to 250 meters in search.

But Shirley’s computer systems were breaking down, and he had to ascend.

A support diver couldn’t find Shirley at their 80-meter meeting point, so he dropped another 40 meters.

He received a message on a slate saying “Dave’s not coming back”.

Days later, divers went to retrieve Shaw’s equipment and discovered both bodies just 20 meters deep.

Attached to the nylon line Shaw had attached to Dreyer’s remains, and become tangled in.

#2 – Tangled and panicked

In 2014, two divers were taken hostage by a 100-meter deep cave system in Norway called Steinugleflaget cave.

In this tale, it was a case of entanglement and panic which lead to fatalities.

The start of the cave is simple. You enter the pond Plura and swim underground for 500 meters to the first cave.

It’s well known as a beautiful dive for recreational diving. But there’s more, for the less faint-hearted.

Go deeper, through narrow channels, pitch-black, ice-cold water, and you reach Steinugleflaget cave. A recipe for only very skilled cave divers!

A group of five set out to dive that day.

Only three returned.

At 110 meters deep, the leading diver, Gronqvist, realized the second, Huotarinen wasn’t behind him. He turned and found Gronqvist tangled in the cord.

He was using his torch to alert of his distress. Gronqvist gave him a cylinder of gas to reduce his carbon dioxide exposure.

But while he was changing his mouthpiece, he swallowed water uncontrollably. Huotarinen died in front of his eyes.

Gronqvist couldn’t free the body, despite his best attempts. He had to carry on.

Due to this delay, Gronqvist had to add a few hours to his decompression stops. He eventually surfaced safely.

Three more divers followed. Rantanen was next, and he managed to negotiate moving past Huotarinen’s dead body. Uusimaki panicked at the scene.

Rantanen was the final diver and tried to assist Uusimaki but without success. He returned the way he came, unfortunately having to leave his two friends’ bodies.

#3 – Trapped in a Blue Hole

New Mex Blue Hole

Shane Thompson became a victim of New Mexico’s Blue Hole in April 2016.

He was a member of the ADM Exploration Foundation, who were given rare permits to explore the underwater caves which were sealed for 40 years.

At the bottom of the spring, there’s a metal grate that stops divers going too deep. It was placed in 1976 after two training divers died. Beneath the grating, there’s a maze of twisting, turning caves.

The Foundation came to the Blue Hole in 2013 in an attempt to further explore the Blue Hole beyond the grating. It took many attempts before they could remove the rocks above the grating.

On a fateful day in question, Thompson was supposed to be on safety duty, outside of the cave, while fellow cave diver Young entered. For unknown reasons, Thompson went in too.

Young tried to exit following a safety line, but silt had been stirred and there was no visibility.

Thompson pulled the line so hard that Young let go. Then as he was feeling for the line, Thompson became wedged against Young in a narrow passage about 35 meters deep.

After freeing themselves, something went wrong and Thompson started to panic.

He took a wrong turn and ended up in an unmapped offshoot leading nowhere. He was trapped.

Young eventually found Thompson, but he was already dead.

Although a tragedy, Thompson’s family said they knew he died doing what he loved. He started diving at a very young age and spent his life working in the industry.

He’d worked for over 20 years as a technical rebreather diver, and was an instructor for the Navy – it was his life.

After the Thompson’s death, Young announced the caves too unsafe and said they should be sealed for good. He said they were the most dangerous caves the Foundation had ever dived.

#4 – Decompression disturbances

In 1991 there was a mysterious cave diving tragedy.

Two dive buddies, Turner and Gavin were mapping caves in Indian Springs in Florida, but only one came back.

During the dive, currents stirred silt and sand. Vis dropped from 30 meters to about 15 centimeters (80 feet to six inches).

They tried to ascend, but the passage out of the cave was blocked. Gavin managed to force his way out but when he returned for his buddy, he was nowhere to be seen.

Four divers who had already exited the water saw the water level bizarrely seemed to have abruptly dropped. Then kick up the silt and sand.

Following the disaster, the diving and geological communities were in tiffs about what exactly had happened.

Having spent years designing a scientific experiment to explore all of the possibilities. In September 2015, over 20 years after the incident, Doron Nof (Professor of Physical Oceanography at Florida State University) concluded what had happened.

The problem arose when the divers were doing their decompression stops. They were ascending within an air pocket, causing gas bubbles to rise to the upper surface of the cave.

The bubbles caused the buoyancy levels in the cave to change. It affected the stability of the rock and sediment in the walls and ceiling of the cave.

So loose limestone, which weighed more, fell from the walls and ceilings of the cave, blocking the narrow passage below.

Imagine a mudslide but underwater.

This is what caused the blocking of their passageway, and of course, the stirring up of the bottom, causing total visibility blackout.

#5 – Stirred up silt

tank caves

Agnes Milowka, a stunt diver, tragically died in an event strangely similar to that she had acted in the movie ‘Sanctum’.

Agee just 29, the labyrinth of tunnels at Tank Caves in Australia, took her life in February 2011.

Milowka was an adventurous cave diver, who loved exploring to an obsessive degree.

Her skilled cave diving abilities led to her involvement in many documentaries and diving projects.

Mount Gambier in South Australia is famous for its complex combination of sinkholes, caves, and kilometers of underground waterways.

Tank Caves requires expert navigation, through tight restrictions and often limited visibility.

A lot of the cave system is very fragile. The walls and ceiling are soft, and you have to breathe carefully.

If you exhale too hard, the bubbles displace the ceiling, which falls on you!

Causing bad vis, or worse, small restrictions to become even tighter.

Milowka dived at Tank Caves many times and knew it well. Yet, somehow during her last dive, she became separated from her dive buddy.

She became lost after stirring up silt from the cave walls and floor. She wasn’t quite able to find her way out of the cave and ran out of air while doing so.

Evidence suggests she remained very calm until her last breath.

On the day she died, no one’s sure of exactly what happened. She appeared to leave her buddy and never returned. They identified the location she was last seen, but never what caused her to die.

The following day, her body was recovered about 500 meters from the entrance of the cave.

How to survive cave diving

Cave diving isn’t easy. It’s a discipline only for the most meticulous of divers. If you’re prepared to take on the risks, the magical underwater world of caves awaits you.

Every single one of the divers from the unfortunate tragedies was extremely experienced. Despite this, they still met their fate while cave diving.

Cave diving involves a lot of risks that you can’t eliminate. But you can manage and minimize.

Here are five things you can do to survive cave diving.

Do proper training and use good equipment

These are critical. Without them, cave diving is a death trap.

Depending on the qualifying body you go with, you need:

  • A minimum number of logged dives
  • At least an Advanced Open Water or Rescue diver
  • Cave diving certification
  • Proven record with night diving and deep diving.

Experience using a twin-tank system, or sidemount is important. A lot of cave diving is in cold water, so you may need your drysuit qualification too.

One of the biggest risks of cave diving is narrow passages. You’re very bulky with all your gear on – and not getting snagged is an art.

Basic skills like buoyancy are paramount to survival while cave diving. In deep, cold water, a tear in a dry suit on a sharp cave wall could result in death.

Have a guideline

Some of the unique risks of cave diving are the high chances of getting lost, and poor visibility.

Caves are often complex systems with tunnels – which can be difficult to find your way back out of.

They’re also notorious for bad visibility.

The water could be crystal clear to start, but disturbing the silt with your fins could cause absolutely no visibility on your way back out.

Always have a reel or a guideline to your exit. Clip arrows on the line to the direction out of the cave. It’s your means of navigation.

Reserve enough air

Scuba diving air

Air safety is of ultimate importance while cave diving.

In a cave, if you have an out of air situation, you can’t simply share your buddy’s air supply and surface – or do a controlled emergency ascent.

Often when cave diving, you’re doing decompression diving. That means you’ve been at such depth, or for such a long time, that excess nitrogen builds up in your body.

If you surface too fast or too soon, it’s like shaking up a fizzy drink and opening it. Nitrogen bubbles fizz out and get stuck in your body, or brain, and could kill you.

So monitoring your air supply is even more crucial than normal. You need to reserve enough to navigate out of the cave and to do decompression stops.

Have too many lights

When cave diving, you can be in perpetual darkness. So, of course, you have to bring your own dive light with you.

Lots of it!

The cave diving motto is “Three lights is two, two lights are one, and one light is none”.

If your flashlight goes out and you don’t have a backup, you can’t just surface. You’ve got some complicated navigating to do to get back to air.

Each flashlight you take on a cave dive should be able to burn for the entire dive.

Don’t go too deep or too far

Most cave diving accidents happen because people push the limits of their training and experience.

This is when things go wrong. Going deeper, or further than planned can cause exponentially more difficulties than on an open water dive.

Always dive within your limits, and within your plan.

For those brave enough to descend into the depths, with specialized training and careful preparation and diving, you can explore a whole new world. It’s like nowhere else on earth.

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Tash Editor

Tash is a Divemaster, marine conservationist and digital marketer. She loves animals, adventures, the ocean, and chasing an endless summer! She was born in Canada, grew up in the UK, and is currently living in Aussie where the waters are (sometimes!) warmer.

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