I’m a qualified and experienced cave diver – here’s the frightening challenge the boys faced in the Thai cave rescue

Kera Rolson Harry Averill

Picture yourself underwater, deprived of the ability to hear or see, bracing against a frigid current, and trying to fit through a hole so small you must push the air tank that’s keeping you alive in front of you.

In the summer of 2002, I found myself in that scenario attempting to navigate what is called a “no mount restriction”. I was a fully trained and qualified cave diver, and I was still nervous: heart pounding, breathing hard, and intensely aware of the ten meters of water and rock that stood between me and the surface.

I successfully completed that dive as a fit and healthy 20-year-old, filled with the sense of invincibility only a young adult can possess.

To understand what the cave rescue in Thailand was like, imagine the scenario above but you are a young man, starving and weak with fatigue. You’ve been separated from the surface and your family for two weeks. Your only way out is through the unknown murky depths that have sequestered you.

You have no cave dive training but now must learn to do it if you are going to live.

Kera Rolson Harry Averill

At its heart, cave diving is exactly what it sounds like: scuba diving in a submerged tunnel. However, there are some very important differences between diving in a cave and doing it in open water.

Cave diving differs from open water in three main ways: environment, training, and the gear. First, the environment: open water divers are not certified to enter any areas that are covered overhead like a wreck, cavern, or cave. In the open water, you’re likely in a well-lit area, with low current, and a low risk of death. If there’s a problem, you can ascend and go back to your boat. Entering the water for a cave dive, you can already see that cave diving is a different beast. First, you pass from open water to the cavern, an open space where daylight can still light your way. However, the line between cave and cavern is drawn where sunlight ends; if you can no longer see sunlight, you’ve entered the cave.

The cave and its overhead present unique challenges. In an emergency, an open water diver can choose a direct ascent, even risking decompression sickness and a trip to the decompression chamber in an extreme emergency. However, this is not an option for a cave diver.

In the event of a medical emergency or catastrophic gear failure, the only way out is the way in, making the long trek back the way you came. That way back out can be fraught with narrow passageways and silty floors that wreak havoc on visibility.

Inside the Thai cave Linh Pham/Getty Images

These challenges bring us to the second difference: training. It takes a lot to train a cave diver: a full open water certification, lots of experience, then even more specialized training, like how to find the guideline in near zero visibility – a skill crucial to a safe exit. Cave divers also must learn new kicking skills and practice precise buoyancy control to keep from disturbing a silty floor and further impeding visibility.

They also must learn different gas management techniques. Open water allows you to begin ascending when you reach your decompression limits. In cave diving, one carefully manages their gas to turn around when they’ve used one-third of their supply. This ensures you have twice the necessary gas to get back out in case of an emergency that requires you to share air.

This leads to the third difference between open water and cave diving: gear. Cave divers carry everything an open water diver carries, minus the snorkel which could create a safety hazard by becoming entangled in lines or rocky outcroppings.

Their wetsuits are thicker for the colder water, fins are stiffer for fighting currents, and they will usually carry two tanks. In addition to the standard open water gear, they will also carry three lights and a spare reel of line. Finally, they rig up their gear to keep from having “the dangles,” free-floating gear that can get snagged or entangled.

The Thailand cave rescue sharply illustrates the differences between cave and open water diving. What they have likely not told the boys and their coach is that since cave diving became a sport in the 1950s, over 300 people have died in caves. I have personally known three.
My dive buddy from a trip in 2001 died four years ago, an event that caused me to rethink my participation in the sport and drastically reduce the number of dives I do.

Given the hazards of the environment, the training, and gear required, it’s easy to see how 300 people have perished.

Kera Rolson Harry Averill

Now envision yourself in Thai cave environment: starving, weak with fatigue, and scared. These are not the ideal cave diving students; they are the very opposite. It puts in perspective that the choice to train them was truly life and death.

The rescue divers faced the same dangers any other cave diver faces, with one addition: a dive “buddy” who cannot help. They lacked the training or experience you desire in a typical dive buddy whose gear would typically provide redundancy. This is likely why the boys were escorted out by multiple qualified divers, acting as each other’s buddies as they escorted each boy.

I have only the utmost respect for the rescue that occurred. Given the additional dangers imposed by the scenario, these rescue divers embody selfless heroism. Every boy who came out of that cave alive is a testament to the indomitable human spirit.

Kera “Puff” Rolsen is a strategist and certified cave diver. She tweets at @Where_is_Puff.