Freediving Blackout

Freediving is an amazing underwater sport that many people across the world participate in. Unfortunately, many of the participants are unaware of how to enjoy this sport in a safe manner.

Last year in the US, there were around 90 deaths caused from freediving blackout. Almost all of these fatalities occurred with freedivers who were spearfishing. The circumstances of most of these fatalities are very similar, and easy to prevent. For almost all untrained freedivers, a freediving blackout turns into a fatality. For a properly trained freediver, a blackout just means that you are done diving for the day.

Let’s look at a typical freediving blackout. Bob hits the surface and starts to blackout after pulling up a big fish. Bob’s “buddy” is 50 ft down the reef line scouting for fish. When Bob is blacking out, he lets out almost all of the air he was holding in his lungs. Since he is over weighted, when he lets his air out, he starts rapidly sinking to the bottom. Bob’s buddy is wondering where Bob is, so he pops his head up to look for him. At this point Bob has already sunk to the bottom. Two minutes later Bob is most likely face down on the bottom. He will eventually take a “terminal gasp” which will be his last breath. This fictitious fatality can be EASILY avoided by following 3 simple safety rules.

Rule #1. Always dive in a buddy team, employing direct supervision. Dive one up one down. This means that as your buddy is underwater, your sole focus is their safety, not chasing fish. When they surface, you want to be within arm’s reach of them, so if they had a freediving blackout, you would be close enough to grab them and keep their head above water.

Rule #2. Watch your buddy at the surface for no less than 30 seconds. We know that most freediving blackouts happen after the freediver surfaces, and after they have taken a few good breaths. After 30 seconds of breathing, you know that the diver will be ok, and you can go about your business. Unfortunately we know of fatalities where the buddy didn’t follow this rule. The buddy saw the person surface and since the diver looked ok, the buddy began a dive. When the buddy surfaced, he couldn’t find the original diver, as the original diver had blacked out and sank to the bottom. Watch your buddy at the surface for no less than 30 seconds.

Rule #3. Never dive over weighted. Trained freedivers weight themselves such that if they were to blackout, they would end up floating on the surface, as opposed to sinking to the bottom of the ocean. When you get in the water with your gear on, take a breath and do a relaxed exhale (like a sigh) and don’t move your feet or your hands. Once you exhale, you want to make sure you don’t sink to the bottom. If you fail this weighting test and continue to dive, you are telling yourself, if you blackout you would prefer to end up on the bottom of the ocean as opposed to floating on the surface.

Rule of 9’s

90 % of the freediving blackouts happen at the surface after the diver takes 2 or 3 breaths. It is very common during a blackout, for the person to be looking at their buddy and signaling that they are ok as they are blacking out.

9% of the freediving blackouts happen between 15ft and the surface.

These are some basic safety rules that if all freedivers followed, would eliminate most of the fatalities. That being said, reading an article on the internet is not a substitute for taking a freediving class, just like reading ScubaBoard is not a substitute for taking a scuba course. Luckily for us, freediving blackouts are not common, just like a regulator malfunctioning on scuba is not common. In both circumstances you can’t stop the event from happening with any amount of certainty. The only logical thing to do is have a safety procedure in place that would help you deal with the situation effectively if it happened. In a freediving class, you will learn rescue techniques that will allow you to revive a diver who is blacked within around 5 seconds. You will leave feeling confident to respond to a freediving blackout.

Ted Harty is a PFI Instructor and runs PFI freediving classes in South Florida through Immersion Freediving. Information about his freediving classes can be found at