Joshua Chaffee
Joshua Chaffee

Jun 29. 3 mins


Some consider the sport of freediving, or apnea, not only dangerous — but death-defying, and back when apnea was first banned from CMAS, one of the two governing bodies of freediving, many viewed freedivers as insane adrenaline junkies fueled by an addictive rockstar persona.

But is that how it is?

Just ask a freediver, and they will explain to you that apnea isn’t as insane as you might think. They aren’t just adrenaline junkies looking for their next rush at the risk of their lives. Freediving is a sport, like many others, which involves risks. However, these are managed risks, and when done correctly by a trained freediver the risk to life is typically very low.

If you are looking to get involved in freediving, you have to be careful that you take your safety seriously. When performed alone by an untrained freediver, apnea can be deadly.

The Shallow Water Blackout — A Freediver’s Biggest Killer?

Healthy, young freedivers can be diving in shallow water for times well within their limits and, without feeling any need to breathe, blackout on ascent.

What does this mean for someone freediving alone?

Certain death.

For a long time, shallow water blackouts were not well understood. Freediving as a sport is relatively new on the world scene when compared to ancient freedivers who accomplished necessary duties without the aid of compressed air, not because they didn’t want it, but because it just wasn’t available.

For groups like the Jeju Hanyeo, Korean freediving women who have made their living from fishing abalone since the 17th century and continue to do so today, freediving blackouts were simply accepted as an unfortunate occurrence. Hundreds of these women have died due to blackouts through the centuries.

Thankfully, as history has progressed, we have begun to understand shallow water blackouts a little better and are now more equipped to avoid the loss of life associated with them.

What is Involved in a Shallow Water Blackout?

A shallow water blackout, or freediving blackout, is a type of hypoxic blackout. Your brain doesn’t receive the oxygen it needs, so you simply blackout in the middle of a dive.

What makes this type of blackout so dangerous, is that many freedivers feel no need to breathe before it strikes. The mechanism that triggers that need to breathe surprisingly doesn’t come from low oxygen levels; it comes from high CO2 levels.

This means that your brain can be dangerously low on oxygen, and as long as your CO2 levels are still low, you won’t have any symptoms that will warn you of an imminent blackout.

On the contrary, hypoxia can cause a detached mental state that can embolden you to continue going deeper or to push your dive for longer!

To make matters even worse: during a regular drowning incident, the victim has about 8 minutes before brain damage can set in. When it comes to a shallow water blackout, however, the victim has as low as 2.5 minutes before brain damage is a risk. This is because, at the point of blackout, the victim’s brain was already deprived of oxygen for some time.

Why Does it Happen?

The main reason that shallow water blackout associated deaths occur is simply a lack of education.

So how can you avoid it?

There is some great information on that you might want to take a look at, but for a simple breakdown of what to do and what not to do, take a look at this:

  1. Get trained professionally by a certified freedive instructor
  2. Always dive with a buddy
  3. Never hyperventilate before a freedive

Can You Get Decompression Sickness From Freediving?

If you ask around, you might get mixed reviews. Some people still believe that decompression sickness (DCS) is impossible for freedivers since they are not breathing compressed air. Unfortunately, those people are ignorant of some facts.

DCS occurs when gasses that have been dissolved into your blood become decompressed and can no longer be held by your blood and turn into bubbles in your bloodstream. It is symptomized by deep and sometimes excruciating joint pain as well as itchy skin. You may experience weakness, confusion, headaches, and a slew of other symptoms including paralysis and death.

DCS, or the bends, is common and dangerous for divers breathing compressed air since there is an excess of gasses that are continuously brought into the body, and at extreme depths, that gas can easily dissolve into the blood. If the diver surfaces rapidly, that gas turns back into bubbles and gives the diver decompression sickness.

When it comes to freediving, however, you are diving on a single breath of air, so you are not bringing in outside gasses to be dissolved into your blood and cause sickness. In all honesty, apnea is much safer when it comes to the bends and is much more difficult to contract.

So where does the danger come from?

  • Freedivers who have recently gone on multiple SCUBA dives in the same day or previous day may be at risk of developing DCS during a deep freedive as extra gas may still be present in their system.
  • Freedivers who make multiple and repetitive dives to 30m or more in succession.
  • Freedivers who take a breath from a tank of compressed air once they are already underwater.

The Truth Behind The Thrill and The Rush

People who assert that freediving is a sport full of thrill seekers and adrenaline junkies have no knowledge about the true community behind freediving. While apnea is fun, and can certainly be considered thrilling, the key to apnea is physical and mental relaxation. A meditative state and a slow heartbeat help you to stay down longer; the exact opposite of a rush of adrenaline.

Calling apnea dangerous and deadly while reporting solely on the deaths and danger instead of the amazing human feats accomplished by inspirational athletes does nothing but damage the sport and the community. The truth is that freediving as a sport is not dangerous when done correctly by an experienced diver.

If you take a professional freediving class, never dive alone, and stay within your limits, then you are at virtually no risk that isn’t already associated with SCUBA diving. Apnea is a safe and enjoyable sport that allows us to observe the wonders of the human body.


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