I got into Freediving back in 2011. It is a serene and sublime activity. I started out on holiday in Spain in a pool that was 3.5 metres deep. It was incredible lying on the floor of the pool for four minutes watching people do lengths 3.5 meters above me, oblivious to the fact that I was there. I had someone watching me though for safety, they were trained in what to do if DWB OR SWB occurred. I now dive in so many wonderful locations. It is SO IMPORTANT that if you ever decide to get involved in Freediving to ALWAYS have someone watching you/a safety diver. Never dive alone as in some cases blackout can occur without warning. Touch wood I've never blacked out however I never really push things to the absolute limit of my breath hold.
Man this guy lived a wonderful life. Traveled the world, did exactly what he wanted. Didn’t have to work any crappy jobs just to survive. I would trade my 67 years for his 39 anytime.
There is no monster in "The Deepest Breathe", but it is one of the scariest films I've ever seen. Watching it causes much anxiety. Water is the scariest natural force . . .
This was such a great intro to freediving physiology! The "mammalian dive response" is a little bit of a misnomer because it's shared by all other vertebrate animals that breathe air, but mammals do have the strongest reflex.
Amazing documentary and a great tribute to the many that lost their lives in a sport they loved and challenged. Before watching, I was unaware there were such a large group of supreme athletes accomplishing such goals. May they all rest in peace and in the hearts for those of us that live with this knowledge, especially the families & close friends. ...104 Flippers - 39 Splashes BTW, I am a non-swimmer but found myself holding my breath through most of the nearly 2 hour filming. MCDJ
To be clear .. there is no 'Many' The ONLY athlete that has died in competition is American Nick Mevoli. He had a pre-disposing condition that he failed to disclose to an anyone and did not self-check himself from diving. He had a deep blackout at 45m (safety divers come in on a dive like his at 30m. So the counter ballast was activated and he was on the surface in about a minute. But because of his condition (lung injury) he was not able to be revived. Stephen's death as seen here was NOT in competition. It was a 'stunt' at the behest of Alessia and series of things went wrong which ended up causing his death. Nick aside, there have been ZERO deaths in competitive freediving. The safety procedures are incredibly good.
I miss that sport. I was doing it as a kid in Europe. Had to stop in the US, where not a single diving pool exist. I can not wait to start again once I move to Africa.
Whoa. So you’re saying that humans really can hold their breath longer when they’re under water? I’ve noticed that since I was a kid. I just thought it was psychological. This explains so much.
This documentary haunted me for weeks!!! Watching people volunteering to risk their lives in this was sad and shocking. Watching some lifeless bodies have to be assisted and pulled up out of the water to be brought back was traumatizing. RIPbto all who didn’t make it.
Hi Mizzy, I thibk you confusing blackouts with Deaths. There is lots of footage of divers being carried to the surface by Sfety Divers, but they do not die. They have just blacked our from hypoxia (their body has burned all the usable oxygen) When you black out underwater your epiglottis stays stopping water from entering your lungs and drowning. As long as you are taken to the surface reasonably (1 - 2 min) before sn unconscious 'gasp reflex' occure, you recover almost immediately and with no known permanent effects. The only death in competitive freediving was Nick Mevoli, but it was later established that a had a predisposing condition he kept to himself. The death of Stephen Kennan was not at an organised competition it was just a personal dive for Alessia at which Stephen agreed to Safety in conjunctin with some others. The reasons why that happened or too detailed for here, but it was unfortunate chain of events. The loss of Natalie Molchanova is puzzling. Again, nt in competition, she was teaching a class to two students. On the surface during the lesson she said to them "Stay here I'll be back in a second in a minute. She never returned and no one knows why. I think the seafloor under them was 'only' 40m. Natalia was capable of over 100m, so that remains very puzzling. If you only hsvr the most basic freediving course and follow the rules. Never dive or train alone. Practice one diver down, one diver up at al times. And only dive with a buddy who is capable of rescuing you ire required. Then deaths are actually non-existent hth
Ну вы можете адресовать точно такие же слова тем, кто летал и продолжает летать на самолетах, ездить на автомобилях и т.п. Вообще жизнь - опасная штука, за миллионы лет еще никому не удалось навсегда остаться в живых. ;)
The description of the lung squeeze wasn't correct. That's not what free divers mean when they talk about lung squeeze. They're talking about the lungs compressing so much as they descend that the sensitive tissue inside squashes against itself causing injury. For normal free diving, lungs expanding as you swim up isn't a problem.
Correct. Normally lungs are very flexible. But as we descend and they are compressed they become less flexible.This in itself is not. problem, Amny divers are reaching depths of 100-130m+ now. Bu as the lungs are compressed the Mammalian Dive Response (MDR) also works by shifting blood from the extremities to the internal organs. This is an adaptation to make these Orans (especially the lungs) incompressible beyond a certain point. This has only been understood in the last 20-25 years and is why in the 70s and 80s the physiologists said "If you go below 60m you will die from lung rupture. They didn't know about the blood shift into the lung tissues. Back to the blood in the lungs. The lung issues are now very inflexible. A 'lung squeeze. Should be more accurately called a 'lung tear' A common way to invoke it is at the turn at the bottom of the dive. As you hit the plate in freewill, you hands are usually by your sides. The you have to tumble tuen and reach out and up your arm to grab the rope for the turn. Stretching your arm up like that puts a stretching stress on the blood engorged lung tissue and a tear occurs. Usyually painless. As you ascend and your lungs re-inflate and blood circulation returns, a small amount of blood from that tear makes its way into the lungs and travels to the airways which us why yu tase and feel blood in your mouth or nose and if you cough (which you feel like doing) you cough up blood. It's far from fatal and whilst not common, also not unusual. Average recreational freedivers going to say 50m get squeezes. Thew anser is slow and steady adaptation. Excersies to increase your lung capacity and felxilibity and care with technique not to induce a tear. hth
Very good and very well researched explainer. 👍🏻 Just the thing about the mammalian dive reflex. Many call it that but it seems that we share it with all vertebrates that have evolved after our ancestors have left the sea. I think it's wonderful that we share such trait with so many other species. ☺
I just saw The deepest breath (netflix 2023) and I was surprised how unsafe they dived the Blue Hole, Dahab where Stephan died. Can someone explain why its not safer? - They had two ropes leading to a fixed point at 55m. Why didnt they use a horizontal rope that connected both ropes. Then she wouldnt get lost and stephan had survied - Why is they no lights connected to the deepeest part of the rope so you dont miss it. Also the safety diver and the freediver could have lights? - Why was Stephan the only safety diver? - Why arent there scuba diver for safety? They can drag free divers up when they start to struggle and at the same time can stay below decompression zone
Stephen wasn't the only safety diver .. there were 5 more in water plus a topside team.. Scuba divers don't work for rescuing free divers. By the time they get in position they have incurred a deco obligation so cannot surface.They also run the very real risk of lung barotrauma (fatal) if they came up fast on compressed gas. Other free divers however can surface as fas as they like. In a nutshell,Steven had planned to meet Alessia at a. certain precise time into her dive. But he was delayed in getting off the surface. So she exited the hole in the blue hole and he wasn't there. Secondly she was confused and thought she was still in the hole and followed the awall around to the right. When Stephen to to depth he saw swimming AWAY from him and the safety line and extra Safeties above, so he had to sprint horizontally to catch her start their ascent. When they did surface they were a long way from the other safety divers and took a minute for them to get to them both, by which time Stephen had a surface BO and drowned You can read the official incident report here which has very precise information and you will understand www.aidainternational.org/PostDetails/47
@@deanlaffan2390 thanks for the answer. to me the questions are still not answered fully. Ropes and light scould have prevented getting lost. And they was not safety diver with steve so they were practically alone
@@deanlaffan2390 They still could have positioned a scuba diver at the point where stephen was supposed to meet her, so she would have known where to go. The diver wouldnt have to go up with her but would show her the way
@@iris5789 Agree 100%. For the life of me I don't know why a strobe was not deployed on the plate. Even that would have solved the problem. In spite of Stephen being 20 seconds late. He would have met her at about 40m and this conversation we are having would never exist. Woulda, coulda, shoulda ...
Exactly, and I'm also wondering why they didn't have any ambulances near. I was reading the wikipedia page and, I don't know if this is completely true but, it says that "there was no on-site specialist doctor, insufficient medical equipment, no safety boat, and no ambulance on stand-by at the dive site. Zecchini was inexperienced in open water, was unfamiliar with the Blue Hole, and wanted to tackle it without fins rather than with the usual, more powerful mono-fin. As her safety, Keenan agreed to meet her at −50 m (−160 ft), though the standard limit for safety divers is −30 m (−98 ft)." (en.wikipedia.org/wiki/Alessia_Zecchini) So sad
I do believe it was a mistake in the writing or something like that because the lowest recorded I think it was between 10 and 15 beats per minute. Impressive nonetheless!
Humans are weird. Can you imagine ocean creatures, holding their gills, trying to climb a rope attached to a hot air balloon to see how high they can climb before they pass out and die.
Hundreds of videos on UA-cam and I still could not find the answer to one and most important question. How the hell freedivers overcome this urge to inhale. Why do they rather pass out then inhale water? Still searching the answer...
It's not an urge to inhale, it's urge to exhale. Due to buildup of CO2 your intercostal (interrib) muscles start to contract involuntarily, which makes it quite uncomfortable, especially for a beginner freediver (our body actually senses our oxygenated state through CO2 blood levels, which lower blood pH). With training you can learn to relax your body even when the contractions arise and become more violent. When you become more adept in holding breath you can push yourself to the edge while still not knowing the precise signals that tell you when to stop your breathold. When we stop the long breathhold we exhale, but the oxygen levels in our blood still fall for the next 15 seconds or so. If you do not perform correct recovery breaths you can blackout in that short time period after finish your "dive".
Someone replied with very detailed answer, kudos to him/her. With more practise you get used to holding your breath longer and in deeper waters (aka more pressure pressing against your whole body). I think (I'm not sure) water entering your body, entering your lungs would be worse than passing out and having your airway blocked from drowning. If you black out but your mouth and nose are covered, the chances of you surviving are higher than having your lungs filled with water because (again, I think) when you black out and not get drowned your brain basically shuts down and conserves energy for the brain (itself) in order to ensure you survive, but if you inhale water you're basically fxxked? Not a medic nor a pro in freediving, but it's easier to do medical resuscitation and get someone to recover if they just black out, compared to someone who gulped down water and has their lungs full of it.(? The former normally recovers when you do mouth to mouth resuscitation while the later requires you to be full mode CPR and you have to ensure water exits their lungs in order to survive. During the freediving course they teach you to identify signs that you're running high on CO2 (low on oxygen), which causes your diaphragm to contract and move uncontrollably a lot. That's basically when you know that's the red signal and you should be aware. Still new to freediving so this is just my personal opinion. Nonetheless that's an extremely good question from your end. I'd like to find out the "correct" answer too Cheers mate
@lesteryoung there is a thumb rule that by the time the contractions start your about 2/3 away from blacking out. So 2 minutes breath hold and you get contractions, you could do 1 more minute with your body trying to inhale before you actually BO. And yes of course it’s much worse to swallow water and drown than to be unconscious and get to the surface with your airways closed. Most of the time there is not even need for cpr. You just do the “tip tap blow talk “ and unconscious people will wake up and start breathing, without any major health issues
A former University of Washington Rower, just recently died doing this type of FreeDiving in the Philippines. This hobby or so called sport to some people is very dangerous. You’re pretty much playing with life or death.
A colleague in Morocco got a pretty rare accident: a permanent paraplégie due to a decompression accident.. I visited him in the hospital but it was to late to be improved by a recompression chamber...
@@cottoncandyflossful Yes, I would be and that's why I asked. It seemed as if you meant from freediving, which would be astounding. Unless your name starts with Herbert and ends in Nietcsh ;-)
Hmmm, whats with the blood shift? Yes the mdr is important but without the blood shift that fills our pulmonary vessels with blood, when we really dive deep, prevents for really bad injuries. And most of the lung squeezes are because the blood shift not trained as it should.
Freediving is a pretty amazing feat, and a cool capability to watch people train and get good at. its awesome what the human body can do. just some feedback: this is a video about *the science of freediving*, so stop apologizing whenever you mention physics, as if we're toddlers.
the movie “The deepest breath”paints a completely false picture of freediving as a sport and a competitive discipline. Breaking records at any cost, regardless of the victims, is completely wrong and misleading.
@@GarretGrayCamera exactly! I’m competitive freediver as well, I like records as well, I’m my best competition and sometimes you just have happy with more meaningful things. The best thing in freediving is to dive deep in yourself. But there are still some athletes who play a different game.
The section regarding the lung squeeze is incorrect. Lung squeeze in freediving happens during descent when the blood flows into the lungs and the capillary burst, not during ascent. When you make a video eplaining the physics behind a documentary first you should ensure you are understanding such physics, or misinformation is spread😊
Good video - except for the contrived apologies for including science "I know..I know..I'm sorry.." Ask yourself (if you are the type of creator serious enough to actually try introspection) what you are trying to convey with this narrative technique(?).
I just find this sport suicidal those drivers are coming up for air with there eyes popping out of their heads gasping for air your just playing with death till it gets ya ☠️
"If you traveled to the top of Mount Everest you wouldn't even change one whole atmosphere." Fun fact: If you traveled to the moon you wouldn't even change one whole atmosphere
@@LethalLuggage Yes that's what you subjectively FEEL, but you're not suggesting th actual internal temperature of body is changing are you ? That's not happening.
His video didn't say that the Mt Everest Atmospheric pressure is 0.77 atm. He said that the "Delta pressure" (the triangle symbol used in engineering to indicate the difference or delta) was 0.77atm. So 1-0.77 = 0.23 atm at top of Mt Everest. If pressure at Mt Everest summit is really 0.33 atm, maybe he has typo and delta P should be 0.67 atm.
I know hindsight is 20/20 but ... why do they only hang a single rope on the other side of 'the arc' where Stephen Keenan died? Allesia swam under the arc and couldn't find the rope, but it felt insane to me that they only hang a single rope and not at least three? It's almost pitch black in parts.I wonder if that's how they do it these days.
She needed to meet up with her diving buddy (safety diver) because of the risk of the blackout while surfacing. She would immediately drown if Stephen wouldn’t have watched out for her. And he went down the one line they had, where she was supposed to go up. There are few people in history that could’ve achieved what Stephen did when he went to search her, leave the rope behind, swim to her fullspeed, bring her up to surface and bring her body into a position where she didn’t drown from the blackout (which they both had). He was so selfless that he used his last seconds of conscienceness to do so. 2 more ropes wouldn’t have saved her, because there was only one Stephen… RIP
I thought this as well -- if it was so important for her to not get lost and see that rope to go back up, why not put multiple or put some lights on the rope?
@@tillfischer1908 I think you misunderstood me. Stephen is a superhuman superhero for sure, there's maybe a handful of people on the planet that could have saved her in this situation. BUT... the reason Stephen was put in such a dangerous situation to begin with is because Alessia failed to find the rope she was supposed to use to ascend. If you had at least a few ropes instead of one, it would be much easier to find when you come out from under the arch and the entire situation would have been avoided. Like the other commenter mentioned, even attaching a single light at the bottom of the rope would have helped her find it and Stephen would still be alive today.
@@TH-dg2mm I agree, i was thinking why not have a scuba diver with a torchlight at the exiting end of the cave guide her to where the rope is, hand her over to the safety diver and then the scuba diver could take however long to safely ascend. Very sad incident. I hope more measures are being considered for such dives now and not have the diver completely reliant on one safety diver.
@@TH-dg2mm There wee three ropes and seven safety Divers including Stephen. This following text from the official accident report: "IN-WATER EQUIPMENT Buoy 1 was attached inside the Blue Hole, 5m in front of the reef, on a fixed perpendicular surface line, providing constant positioning. Line set at: -52m. Buoy 2 was outside Blue Hole, in front and in the middle of the Arch exit, and kept in position at all times by SAFETY_F, who was specially briefed by Stephen. Line set at: -55m. Buoy 3 carried a tank of 100% O2 and was kept close to Buoy 2 at all times by SAFETY_G."
We were quite disappointed after the film. So much can be done for real safety, but just neglected.. Blinking LEDs on the lines to easier be found ("she did not find a line"), small emergency breathing bottle.. emergency ascending inflatable balloon.. Blood saturation level based emergency ascending system. All technology is there, one just need to combine all in a working unit. Instead - "He is down there and we dont know whether he is alive", "she did not find a line" and so on.. wtf?! I had an impression they just want to dive and dont want to live.
Hanging an air tank for a freddiver to breathe would be catastrophic. Taking a breath at depth and attempting to make the surface will absolutely 100% give yu ruptured lungs and or an air embolism (bubbles in your blood which lodge in your brain. It is in your basic training in freediving 101 you NEVER take a break h of air from a scuba diver or air tank at depth. Fatal.
@@deanlaffan2390 I see. I rather meant something one could use on last meters. Let's say 20 meters deep, although it is still 2 bars more.. As noted here and in a film, the black out mainly happens on the last meters at an ascend. They probably head up already to the surface and see it and can do nothing, just black out... I know there are many complications, but the way it is now - a risk is too high.
@@TushhsuT The real danger is IN that last 10m. The pressure goes from 2ATA to 1ATA a 50% reduction in pressure and more importantly ... volume. Your lungs only need a small amount of overpressure to rupture (About 10% of Max vol as I recall) There is no place fro any kind of 'emergency tank' in freediving. Remember apart from this high profile death (this was a private dive, not even at a competition) There has only been ONE death in modern organised freediving (Nic Mevoli) who had a pre-disposing condition he did not disclose to organisers, safety team or medical team.. Blackout in comps are common as people push their limits, as side from Nic, deaths are non-existent.
They deployed 3 lines and 7 safety divers, so I don't think its accurate to say 'hardly any' ... There was a sequence of unfortunate events which if any of them had not happened, Stephen would have lived. It's like most air crashes, if any of the things that went wrong didn't occur, the accident woudl not happen because the 'chain' of events is broken.
@@jonbonesmahomes7472 Stephen was ~20 sec late in leaving the surface. Alessia turned the wrong way ... these ar not landing issues they are operational.
I m tired of watching this accident happening in freediving. Can you talk about challenging yourself? the feeling of the water? the sensation and emotion you get when you go deeper and deeper? the fatigue that it cost out of the water? geeze.. I just see people blacking out when it comes about freediving documentary
Socrates said that education is the kindling of a flame not the filling of a😂😂 vessel but this collegiate man wants to fill us up with unnecessary facts. Emotion is stronger than logic . Just tell us the stories of why people like it.We just need to hear what can help us get through the psychological process of gee, I think I could do this or at least take some steps to try a little.
"The bends". Because they're not breathing pressurized gas and they're not spending enough time under pressure for a significant amount of that gas to be absorbed by the tissues of the body. Scuba divers spend tens of minutes at depth.
Air is 79% Nitrogen (N) 21% Oxygen O2. The bends (Decompression Sickness) in scuba divers is because they are breathing compressed air at depth for a decent time. The oxygen is metablised so is irrelevant at what pressure it is at. But we cant use the N, it is what is termed 'inert' to our bodies biology. So it just moves in and our of our lungs and tissues. But underwater (on scuba) our tissues become what's called 'supersaturated' with N, the deep we go and/or the longer we stay the more N we build up. That's OK, the N can find its layout via our lungs as long as we ascend slowly and leave enough time for ll the extra N to get around blood supply, get to the lungs and diffuse out. But free divers take only ONE breath from the surface, take it to depth and return to the surface WITH THE SAME BREATH, so there is no extra load of N from breathing air at depth under greater pressures. There are some unusual situations where DCS in freediving CAN become an issue, but they are not germane to this conversation. Does that make sense ?
The vast majority of freedivers don't die. Sometimes documentaries can make a sport sound more dangerous than it is by focusing on the extremes. It's like watching Air Crash Investigations and forgetting that millions fly each day without issue. I just did the Level 1 Freediver course and can recommend it. It's a very relaxing feeling and it's fun to train your body to do new things. Being able to submerge freely like a fish for minutes is very liberating.
The reason most of these people get into free diving is because all need to learn how to control their minds into relaxation mode. 99.9% of free divers have some type of physical or mental disorder. It becomes dangerous when they do it for competition. I'm planning to take free diving classes to help me cope with anxiety. I will never do it as a sport. I will do it in a pool to help me control my mind. I take ice baths 🛁 with the wim hof breathing techniques. I had a phobia with elevators, It went away within two months after taking ice baths every day. Free diving competition is more of an ego.
@@jennysantiago2624 maybe 99.9% of free divers YOU know have a mental disorder... As an instructor and coach I know hundreds of them, and the % of mental issues is not different than any other sport or work environment. True, free diving as a discipline (not necessary as a competition) has significant, and scientifically proven, effects of neuro empowerment
@@caltomonteI think many people, if not all of us have mental health issuers. Perhaps the difference is that people that are active on water (freediving, sailing, surfing, diving, etc), people with a marine mind are often easy going people and are honest about the mental issues. And the water is a source that gives us calmness, clarity, peace, and happiness. Maybe that’s why she thinks we all have mental health issues, but like you said: I think many people around us, if not all, deal with these problems too. Except they might not have acknowledged it yet, are oblivious to it, are not speaking openly about it because of the environment, or other reasons. But to me, I love the marine environment, I love the communities it’s got, and on all different fronts, they’re all similar people, I just love that.
2:02 "i know netflix is for dumb losers who can't understand bascis science explained at primary school level, but we're gonna include it still" what a company
Maybe the absolute dumbest thing in the universe is “I’m the ‘safety’ guy, you know, the one who is supposed to rescue you if something happens….but I have no air tanks or anything, so I’m just as vulnerable as you “. Ridiculous. That’s like having the lifeguard at your local pool who can’t actually swim….
Safety guy with air tanks wouldn’t save anyone, due to pressure relief stops you need a lot of time to get to the surface with air tanks, the only way to help a free diver having troubles is to bring him to the surface quickly thanks to safety guys holding their breath… stop acting smart if you don’t know shit about the sport, freediving and security issues
"Looks dangerous" need not be equivalent to "is dangerous". In a competition environment, freediving is extremely safe. I say this as a competitive freediver. Please educate yourself about the sport before you make insulting claims about it.
I used Badjao Technic and I can dive alone without taking any risks. A small mistake is very dangerous never pushed your body when your brain tells you to stop. Instincts and Common Sense must be highly used in Freediving.
I got into Freediving back in 2011. It is a serene and sublime activity. I started out on holiday in Spain in a pool that was 3.5 metres deep. It was incredible lying on the floor of the pool for four minutes watching people do lengths 3.5 meters above me, oblivious to the fact that I was there. I had someone watching me though for safety, they were trained in what to do if DWB OR SWB occurred. I now dive in so many wonderful locations. It is SO IMPORTANT that if you ever decide to get involved in Freediving to ALWAYS have someone watching you/a safety diver. Never dive alone as in some cases blackout can occur without warning. Touch wood I've never blacked out however I never really push things to the absolute limit of my breath hold.
Man this guy lived a wonderful life. Traveled the world, did exactly what he wanted. Didn’t have to work any crappy jobs just to survive. I would trade my 67 years for his 39 anytime.
There is no monster in "The Deepest Breathe", but it is one of the scariest films I've ever seen. Watching it causes much anxiety. Water is the scariest natural force . . .
This was such a great intro to freediving physiology! The "mammalian dive response" is a little bit of a misnomer because it's shared by all other vertebrate animals that breathe air, but mammals do have the strongest reflex.
penguin tings
Amazing documentary and a great tribute to the many that lost their lives in a sport they loved and challenged. Before watching, I was unaware there were such a large group of supreme athletes accomplishing such goals. May they all rest in peace and in the hearts for those of us that live with this knowledge, especially the families & close friends. ...104 Flippers - 39 Splashes
BTW, I am a non-swimmer but found myself holding my breath through most of the nearly 2 hour filming.
MCDJ
Watch The Deep Blue (1988). All about freedivers at the beginning of the modern sport. Great movie.
To be clear .. there is no 'Many' The ONLY athlete that has died in competition is American Nick Mevoli. He had a pre-disposing condition that he failed to disclose to an anyone and did not self-check himself from diving. He had a deep blackout at 45m (safety divers come in on a dive like his at 30m. So the counter ballast was activated and he was on the surface in about a minute. But because of his condition (lung injury) he was not able to be revived.
Stephen's death as seen here was NOT in competition. It was a 'stunt' at the behest of Alessia and series of things went wrong which ended up causing his death. Nick aside, there have been ZERO deaths in competitive freediving. The safety procedures are incredibly good.
Free diving fascinates me. This was a great explanation into the physiological aspects of it.
I miss that sport. I was doing it as a kid in Europe. Had to stop in the US, where not a single diving pool exist. I can not wait to start again once I move to Africa.
Come. to Mauritius.
@@lilac524 How did you know I am moving there next year? I will also be there this Christmas.
Whoa. So you’re saying that humans really can hold their breath longer when they’re under water? I’ve noticed that since I was a kid. I just thought it was psychological. This explains so much.
This is really amazing. Even just a wet towel on the face will help holding the breath longer.
I just need to mention La Grand Bleu which introduced me to free diving back in the late 80s. Crazy sport but a beautiful film.
One of my favorite movies. Luc Besson.
I watched this movie as a child and loved it!!! It’s one of the reasons I was driven to watch this doc!
Then there's "Hold Your Breath: The Ice Dive, 2022" . . . that will give you chills!
This was an excellent documentary
This documentary haunted me for weeks!!! Watching people volunteering to risk their lives in this was sad and shocking. Watching some lifeless bodies have to be assisted and pulled up out of the water to be brought back was traumatizing. RIPbto all who didn’t make it.
Hi Mizzy, I thibk you confusing blackouts with Deaths. There is lots of footage of divers being carried to the surface by Sfety Divers, but they do not die. They have just blacked our from hypoxia (their body has burned all the usable oxygen) When you black out underwater your epiglottis stays stopping water from entering your lungs and drowning. As long as you are taken to the surface reasonably (1 - 2 min) before sn unconscious 'gasp reflex' occure, you recover almost immediately and with no known permanent effects. The only death in competitive freediving was Nick Mevoli, but it was later established that a had a predisposing condition he kept to himself.
The death of Stephen Kennan was not at an organised competition it was just a personal dive for Alessia at which Stephen agreed to Safety in conjunctin with some others. The reasons why that happened or too detailed for here, but it was unfortunate chain of events.
The loss of Natalie Molchanova is puzzling. Again, nt in competition, she was teaching a class to two students. On the surface during the lesson she said to them "Stay here I'll be back in a second in a minute. She never returned and no one knows why. I think the seafloor under them was 'only' 40m. Natalia was capable of over 100m, so that remains very puzzling.
If you only hsvr the most basic freediving course and follow the rules. Never dive or train alone. Practice one diver down, one diver up at al times. And only dive with a buddy who is capable of rescuing you ire required. Then deaths are actually non-existent
hth
Ну вы можете адресовать точно такие же слова тем, кто летал и продолжает летать на самолетах, ездить на автомобилях и т.п.
Вообще жизнь - опасная штука, за миллионы лет еще никому не удалось навсегда остаться в живых. ;)
Only 1 person has ever died in competition, freediving is extremely safe and the documentary tried to make it significantly more scary
Not true- it is definitely not extremely safe. It is pushing your body to the brink and trusting that you know your limit.
The description of the lung squeeze wasn't correct. That's not what free divers mean when they talk about lung squeeze. They're talking about the lungs compressing so much as they descend that the sensitive tissue inside squashes against itself causing injury. For normal free diving, lungs expanding as you swim up isn't a problem.
0:47
Correct. Normally lungs are very flexible. But as we descend and they are compressed they become less flexible.This in itself is not. problem, Amny divers are reaching depths of 100-130m+ now. Bu as the lungs are compressed the Mammalian Dive Response (MDR) also works by shifting blood from the extremities to the internal organs. This is an adaptation to make these Orans (especially the lungs) incompressible beyond a certain point. This has only been understood in the last 20-25 years and is why in the 70s and 80s the physiologists said "If you go below 60m you will die from lung rupture. They didn't know about the blood shift into the lung tissues.
Back to the blood in the lungs. The lung issues are now very inflexible. A 'lung squeeze. Should be more accurately called a 'lung tear' A common way to invoke it is at the turn at the bottom of the dive. As you hit the plate in freewill, you hands are usually by your sides. The you have to tumble tuen and reach out and up your arm to grab the rope for the turn. Stretching your arm up like that puts a stretching stress on the blood engorged lung tissue and a tear occurs. Usyually painless. As you ascend and your lungs re-inflate and blood circulation returns, a small amount of blood from that tear makes its way into the lungs and travels to the airways which us why yu tase and feel blood in your mouth or nose and if you cough (which you feel like doing) you cough up blood.
It's far from fatal and whilst not common, also not unusual. Average recreational freedivers going to say 50m get squeezes.
Thew anser is slow and steady adaptation. Excersies to increase your lung capacity and felxilibity and care with technique not to induce a tear.
hth
Correct. And Natalia would not stay underwater for 9 minutes. That time would only refer to static apnea and not open water diving.
The Netflix film "Last Breath, 2018" will blow you away! 😮 and cause much anxiety . . . 😩
i hope no one overlooked, that both, alessia and stephen did find what they were looking for. above water.
Very good and very well researched explainer. 👍🏻
Just the thing about the mammalian dive reflex. Many call it that but it seems that we share it with all vertebrates that have evolved after our ancestors have left the sea. I think it's wonderful that we share such trait with so many other species. ☺
Le Grand Bleu, a beautiful film, always makes me want to get wet, and after this I’m taking a mask and fin’s and go up to the quarry for a dive 🥰
Birkaç gün önce Şahika Ercümen'in 100mt rekoru ile mutlu olduk, bu yapımı da ona istinaden izlemek isterim. 🇹🇷🇹🇷🇹🇷
Why is Boyle's Law accompanied by a graphic of the nonsensical Lorem Ipsum placeholder text instead of the actual law?
I just saw The deepest breath (netflix 2023) and I was surprised how unsafe they dived the Blue Hole, Dahab where Stephan died. Can someone explain why its not safer?
- They had two ropes leading to a fixed point at 55m. Why didnt they use a horizontal rope that connected both ropes. Then she wouldnt get lost and stephan had survied
- Why is they no lights connected to the deepeest part of the rope so you dont miss it. Also the safety diver and the freediver could have lights?
- Why was Stephan the only safety diver?
- Why arent there scuba diver for safety? They can drag free divers up when they start to struggle and at the same time can stay below decompression zone
Stephen wasn't the only safety diver .. there were 5 more in water plus a topside team..
Scuba divers don't work for rescuing free divers. By the time they get in position they have incurred a deco obligation so cannot surface.They also run the very real risk of lung barotrauma (fatal) if they came up fast on compressed gas. Other free divers however can surface as fas as they like.
In a nutshell,Steven had planned to meet Alessia at a. certain precise time into her dive. But he was delayed in getting off the surface. So she exited the hole in the blue hole and he wasn't there. Secondly she was confused and thought she was still in the hole and followed the awall around to the right. When Stephen to to depth he saw swimming AWAY from him and the safety line and extra Safeties above, so he had to sprint horizontally to catch her start their ascent. When they did surface they were a long way from the other safety divers and took a minute for them to get to them both, by which time Stephen had a surface BO and drowned
You can read the official incident report here which has very precise information and you will understand www.aidainternational.org/PostDetails/47
@@deanlaffan2390 thanks for the answer. to me the questions are still not answered fully.
Ropes and light scould have prevented getting lost.
And they was not safety diver with steve so they were practically alone
@@deanlaffan2390 They still could have positioned a scuba diver at the point where stephen was supposed to meet her, so she would have known where to go. The diver wouldnt have to go up with her but would show her the way
@@iris5789 Agree 100%. For the life of me I don't know why a strobe was not deployed on the plate. Even that would have solved the problem. In spite of Stephen being 20 seconds late. He would have met her at about 40m and this conversation we are having would never exist.
Woulda, coulda, shoulda ...
Exactly, and I'm also wondering why they didn't have any ambulances near. I was reading the wikipedia page and, I don't know if this is completely true but, it says that "there was no on-site specialist doctor, insufficient medical equipment, no safety boat, and no ambulance on stand-by at the dive site. Zecchini was inexperienced in open water, was unfamiliar with the Blue Hole, and wanted to tackle it without fins rather than with the usual, more powerful mono-fin. As her safety, Keenan agreed to meet her at −50 m (−160 ft), though the standard limit for safety divers is −30 m (−98 ft)." (en.wikipedia.org/wiki/Alessia_Zecchini)
So sad
5 beats per minute. Wow my jaw dropped. That’s pretty cool.
I do believe it was a mistake in the writing or something like that because the lowest recorded I think it was between 10 and 15 beats per minute. Impressive nonetheless!
Humans are weird. Can you imagine ocean creatures, holding their gills, trying to climb a rope attached to a hot air balloon to see how high they can climb before they pass out and die.
whales do the same thing
Humans are ultra adaptable. That's their biggest strength. Ocean creatures are ultra specialized
@@BlorbusUnimax lol true. mammals.
@@strahinja95 i love your comment. true that.
Some of them would if they weren't just animals
this was way more interesting I thought it would be
This is one of the coolest things ever
Hundreds of videos on UA-cam and I still could not find the answer to one and most important question. How the hell freedivers overcome this urge to inhale. Why do they rather pass out then inhale water? Still searching the answer...
It's not an urge to inhale, it's urge to exhale. Due to buildup of CO2 your intercostal (interrib) muscles start to contract involuntarily, which makes it quite uncomfortable, especially for a beginner freediver (our body actually senses our oxygenated state through CO2 blood levels, which lower blood pH). With training you can learn to relax your body even when the contractions arise and become more violent. When you become more adept in holding breath you can push yourself to the edge while still not knowing the precise signals that tell you when to stop your breathold. When we stop the long breathhold we exhale, but the oxygen levels in our blood still fall for the next 15 seconds or so. If you do not perform correct recovery breaths you can blackout in that short time period after finish your "dive".
@@ernestocelestine2189 Thank you for your answer. It gave me more info then hours of videos!
It’s the power of the mind
Someone replied with very detailed answer, kudos to him/her. With more practise you get used to holding your breath longer and in deeper waters (aka more pressure pressing against your whole body).
I think (I'm not sure) water entering your body, entering your lungs would be worse than passing out and having your airway blocked from drowning. If you black out but your mouth and nose are covered, the chances of you surviving are higher than having your lungs filled with water because (again, I think) when you black out and not get drowned your brain basically shuts down and conserves energy for the brain (itself) in order to ensure you survive, but if you inhale water you're basically fxxked?
Not a medic nor a pro in freediving, but it's easier to do medical resuscitation and get someone to recover if they just black out, compared to someone who gulped down water and has their lungs full of it.(? The former normally recovers when you do mouth to mouth resuscitation while the later requires you to be full mode CPR and you have to ensure water exits their lungs in order to survive.
During the freediving course they teach you to identify signs that you're running high on CO2 (low on oxygen), which causes your diaphragm to contract and move uncontrollably a lot. That's basically when you know that's the red signal and you should be aware.
Still new to freediving so this is just my personal opinion. Nonetheless that's an extremely good question from your end. I'd like to find out the "correct" answer too
Cheers mate
@lesteryoung there is a thumb rule that by the time the contractions start your about 2/3 away from blacking out. So 2 minutes breath hold and you get contractions, you could do 1 more minute with your body trying to inhale before you actually BO.
And yes of course it’s much worse to swallow water and drown than to be unconscious and get to the surface with your airways closed. Most of the time there is not even need for cpr. You just do the “tip tap blow talk “ and unconscious people will wake up and start breathing, without any major health issues
A former University of Washington Rower, just recently died doing this type of FreeDiving in the Philippines. This hobby or so called sport to some people is very dangerous. You’re pretty much playing with life or death.
A colleague in Morocco got a pretty rare accident: a permanent paraplégie due to a decompression accident.. I visited him in the hospital but it was to late to be improved by a recompression chamber...
From freediving or from scuba ?
freediving/ hunting
@@deanlaffan2390
@@deanlaffan2390 more likely from scuba i think
@@cottoncandyflossful Yes, I would be and that's why I asked. It seemed as if you meant from freediving, which would be astounding. Unless your name starts with Herbert and ends in Nietcsh ;-)
Hmmm, whats with the blood shift? Yes the mdr is important but without the blood shift that fills our pulmonary vessels with blood, when we really dive deep, prevents for really bad injuries. And most of the lung squeezes are because the blood shift not trained as it should.
Freediving is a pretty amazing feat, and a cool capability to watch people train and get good at. its awesome what the human body can do.
just some feedback: this is a video about *the science of freediving*, so stop apologizing whenever you mention physics, as if we're toddlers.
the movie “The deepest breath”paints a completely false picture of freediving as a sport and a competitive discipline. Breaking records at any cost, regardless of the victims, is completely wrong and misleading.
@@GarretGrayCamera exactly! I’m competitive freediver as well, I like records as well, I’m my best competition and sometimes you just have happy with more meaningful things. The best thing in freediving is to dive deep in yourself. But there are still some athletes who play a different game.
Loved it❤️
The section regarding the lung squeeze is incorrect. Lung squeeze in freediving happens during descent when the blood flows into the lungs and the capillary burst, not during ascent. When you make a video eplaining the physics behind a documentary first you should ensure you are understanding such physics, or misinformation is spread😊
One day i will do this ❤ ive wanted to so badly since i was a kid
Oh wow❤
It is scary diving in water for many persons
05:21
*Yeah* i can lower my heart rate with my mind i just focus on it and voila.
Mastered mdr.
Good video - except for the contrived apologies for including science "I know..I know..I'm sorry.." Ask yourself (if you are the type of creator serious enough to actually try introspection) what you are trying to convey with this narrative technique(?).
Relax. People find this technique entertaining and makes things interesting. Not all science explanations need to be boring, single-toned monologues.
I just find this sport suicidal those drivers are coming up for air with there eyes popping out of their heads gasping for air your just playing with death till it gets ya ☠️
2:06 So Boyle's law is literally just a Lorem Ipsum text placeholder
Very well explained, thanks!
Being underwater makes it even harder for me to hold my breath
They also lift weights do rowing and bench press
Amazing👍🏻
Brilliant explanation of diving physics, thank you.
crazy
Very approachable, well done !
From pressure and ears have openings
"If you traveled to the top of Mount Everest you wouldn't even change one whole atmosphere."
Fun fact: If you traveled to the moon you wouldn't even change one whole atmosphere
So is the mammalian dive reflex the thing that also causes dipping your head into the water to make the water around you less cold?
No that is just your face adapting to the cold. But the MDR is enhanced the colder the water. Not massively, but still ...
@@deanlaffan2390 it makes the body less cold as well. I can be freezing cold and then dip my face under and be fine when I come up
@@LethalLuggage Yes that's what you subjectively FEEL, but you're not suggesting th actual internal temperature of body is changing are you ? That's not happening.
It is so saddening too see happen
Is that why I feel like time slows down when I'm snorkeling?
Mt Everest atmospheric pressure is not 0.77 atm. It's rather 0.33 atm. It is a huge difference.
His video didn't say that the Mt Everest Atmospheric pressure is 0.77 atm. He said that the "Delta pressure" (the triangle symbol used in engineering to indicate the difference or delta) was 0.77atm. So 1-0.77 = 0.23 atm at top of Mt Everest. If pressure at Mt Everest summit is really 0.33 atm, maybe he has typo and delta P should be 0.67 atm.
@@erictriplett33 Correct.
Life's under water
I watched this
I think they transform their whole body
I know hindsight is 20/20 but ... why do they only hang a single rope on the other side of 'the arc' where Stephen Keenan died?
Allesia swam under the arc and couldn't find the rope, but it felt insane to me that they only hang a single rope and not at least three? It's almost pitch black in parts.I wonder if that's how they do it these days.
She needed to meet up with her diving buddy (safety diver) because of the risk of the blackout while surfacing. She would immediately drown if Stephen wouldn’t have watched out for her. And he went down the one line they had, where she was supposed to go up. There are few people in history that could’ve achieved what Stephen did when he went to search her, leave the rope behind, swim to her fullspeed, bring her up to surface and bring her body into a position where she didn’t drown from the blackout (which they both had). He was so selfless that he used his last seconds of conscienceness to do so. 2 more ropes wouldn’t have saved her, because there was only one Stephen… RIP
I thought this as well -- if it was so important for her to not get lost and see that rope to go back up, why not put multiple or put some lights on the rope?
@@tillfischer1908 I think you misunderstood me.
Stephen is a superhuman superhero for sure, there's maybe a handful of people on the planet that could have saved her in this situation.
BUT... the reason Stephen was put in such a dangerous situation to begin with is because Alessia failed to find the rope she was supposed to use to ascend.
If you had at least a few ropes instead of one, it would be much easier to find when you come out from under the arch and the entire situation would have been avoided.
Like the other commenter mentioned, even attaching a single light at the bottom of the rope would have helped her find it and Stephen would still be alive today.
@@TH-dg2mm I agree, i was thinking why not have a scuba diver with a torchlight at the exiting end of the cave guide her to where the rope is, hand her over to the safety diver and then the scuba diver could take however long to safely ascend. Very sad incident. I hope more measures are being considered for such dives now and not have the diver completely reliant on one safety diver.
@@TH-dg2mm There wee three ropes and seven safety Divers including Stephen. This following text from the official accident report:
"IN-WATER EQUIPMENT
Buoy 1 was attached inside the Blue Hole, 5m in front of the reef, on a fixed perpendicular surface line, providing constant positioning. Line set at: -52m. Buoy 2 was outside Blue Hole, in front and in the middle of the Arch exit, and kept in position at all times by SAFETY_F, who was specially briefed by Stephen. Line set at: -55m. Buoy 3 carried a tank of 100% O2 and was kept close to Buoy 2 at all times by SAFETY_G."
We were quite disappointed after the film. So much can be done for real safety, but just neglected..
Blinking LEDs on the lines to easier be found ("she did not find a line"), small emergency breathing bottle.. emergency ascending inflatable balloon.. Blood saturation level based emergency ascending system. All technology is there, one just need to combine all in a working unit.
Instead - "He is down there and we dont know whether he is alive", "she did not find a line" and so on.. wtf?!
I had an impression they just want to dive and dont want to live.
Hanging an air tank for a freddiver to breathe would be catastrophic. Taking a breath at depth and attempting to make the surface will absolutely 100% give yu ruptured lungs and or an air embolism (bubbles in your blood which lodge in your brain. It is in your basic training in freediving 101 you NEVER take a break h of air from a scuba diver or air tank at depth. Fatal.
@@deanlaffan2390 I see.
I rather meant something one could use on last meters. Let's say 20 meters deep, although it is still 2 bars more.. As noted here and in a film, the black out mainly happens on the last meters at an ascend. They probably head up already to the surface and see it and can do nothing, just black out... I know there are many complications, but the way it is now - a risk is too high.
@@TushhsuT The real danger is IN that last 10m. The pressure goes from 2ATA to 1ATA a 50% reduction in pressure and more importantly ... volume. Your lungs only need a small amount of overpressure to rupture (About 10% of Max vol as I recall)
There is no place fro any kind of 'emergency tank' in freediving.
Remember apart from this high profile death (this was a private dive, not even at a competition) There has only been ONE death in modern organised freediving (Nic Mevoli) who had a pre-disposing condition he did not disclose to organisers, safety team or medical team.. Blackout in comps are common as people push their limits, as side from Nic, deaths are non-existent.
The documentary was so disturbing because there were hardly any safety measures in such a dangerous environment
They deployed 3 lines and 7 safety divers, so I don't think its accurate to say 'hardly any' ... There was a sequence of unfortunate events which if any of them had not happened, Stephen would have lived. It's like most air crashes, if any of the things that went wrong didn't occur, the accident woudl not happen because the 'chain' of events is broken.
@@deanlaffan2390Its not really the same.
Air crash ,the plane has a techical error,here they made errors in pre planning.
@@jonbonesmahomes7472 Stephen was ~20 sec late in leaving the surface. Alessia turned the wrong way ... these ar not landing issues they are operational.
Tragic tragic tragic ,but some people are courageous.
Fatima Korok Just broke the world record mentioned in the docu :)
I m tired of watching this accident happening in freediving. Can you talk about challenging yourself? the feeling of the water? the sensation and emotion you get when you go deeper and deeper? the fatigue that it cost out of the water? geeze.. I just see people blacking out when it comes about freediving documentary
I watched this 3 times and i still dont understand. Am i stupid??
Why is the narrator apologizing for physics?
And boasting about not knowing what the spleen does?
1:13 wow that's crazy that karl marx actually died while freediving rip to a real one proletarians pour one out for your boy
I can jump off the bridge does that mean I'm tryna do it just because I can 😂 no but it's cool to know we as humans can endure that ❤
Peliculasa❤
Besides humans what animals can deepdive other than fish
sperm whales dive to 1000m
Every marine mammal and penguins at least. Polar bears dive too.
It is fantastic movie so sad
Don't apologize every time you mention physics, laying bare the assumption you think your audience are idiots.
just drink the potion of water breathing
Should be called: The last breath. Sad story…
👏
Socrates said that education is the kindling of a flame not the filling of a😂😂 vessel but this collegiate man wants to fill us up with unnecessary facts. Emotion is stronger than logic . Just tell us the stories of why people like it.We just need to hear what can help us get through the psychological process of gee, I think I could do this or at least take some steps to try a little.
Its not free diving when you're helped up to the top
Dear lord please stop with the weird anti intellectualism
Huh?
@@kac5318I think he may be referring to the narrator trying to be relatable by complaining at the mention of physics
Why dont' they suffer the benz?
"The bends". Because they're not breathing pressurized gas and they're not spending enough time under pressure for a significant amount of that gas to be absorbed by the tissues of the body.
Scuba divers spend tens of minutes at depth.
Air is 79% Nitrogen (N) 21% Oxygen O2.
The bends (Decompression Sickness) in scuba divers is because they are breathing compressed air at depth for a decent time. The oxygen is metablised so is irrelevant at what pressure it is at. But we cant use the N, it is what is termed 'inert' to our bodies biology. So it just moves in and our of our lungs and tissues. But underwater (on scuba) our tissues become what's called 'supersaturated' with N, the deep we go and/or the longer we stay the more N we build up. That's OK, the N can find its layout via our lungs as long as we ascend slowly and leave enough time for ll the extra N to get around blood supply, get to the lungs and diffuse out.
But free divers take only ONE breath from the surface, take it to depth and return to the surface WITH THE SAME BREATH, so there is no extra load of N from breathing air at depth under greater pressures.
There are some unusual situations where DCS in freediving CAN become an issue, but they are not germane to this conversation.
Does that make sense ?
I don’t understand how this sport can be fun. Not worth losing your life for.
The vast majority of freedivers don't die. Sometimes documentaries can make a sport sound more dangerous than it is by focusing on the extremes. It's like watching Air Crash Investigations and forgetting that millions fly each day without issue.
I just did the Level 1 Freediver course and can recommend it. It's a very relaxing feeling and it's fun to train your body to do new things. Being able to submerge freely like a fish for minutes is very liberating.
The reason most of these people get into free diving is because all need to learn how to control their minds into relaxation mode.
99.9% of free divers have some type of physical or mental disorder.
It becomes dangerous when they do it for competition.
I'm planning to take free diving classes to help me cope with anxiety.
I will never do it as a sport.
I will do it in a pool to help me control my mind.
I take ice baths 🛁 with the wim hof breathing techniques. I had a phobia with elevators, It went away within two months after taking ice baths every day.
Free diving competition is more of an ego.
@@jennysantiago2624 maybe 99.9% of free divers YOU know have a mental disorder... As an instructor and coach I know hundreds of them, and the % of mental issues is not different than any other sport or work environment.
True, free diving as a discipline (not necessary as a competition) has significant, and scientifically proven, effects of neuro empowerment
Don’t you know they are Atlantean ? Just pretend among with human, that deep should be very fine for them.
@@caltomonteI think many people, if not all of us have mental health issuers. Perhaps the difference is that people that are active on water (freediving, sailing, surfing, diving, etc), people with a marine mind are often easy going people and are honest about the mental issues. And the water is a source that gives us calmness, clarity, peace, and happiness. Maybe that’s why she thinks we all have mental health issues, but like you said: I think many people around us, if not all, deal with these problems too. Except they might not have acknowledged it yet, are oblivious to it, are not speaking openly about it because of the environment, or other reasons. But to me, I love the marine environment, I love the communities it’s got, and on all different fronts, they’re all similar people, I just love that.
Nine minutes
Why would anyone willingly participate in this sport???
2:02 "i know netflix is for dumb losers who can't understand bascis science explained at primary school level, but we're gonna include it still" what a company
zucchini lmao
Thanks allah I stay for days under the water. John the joker 🃏
Jesus can change your life ❤
I watched this documentary last night. All I can say is what a stupid sport.
Maybe the absolute dumbest thing in the universe is “I’m the ‘safety’ guy, you know, the one who is supposed to rescue you if something happens….but I have no air tanks or anything, so I’m just as vulnerable as you “. Ridiculous. That’s like having the lifeguard at your local pool who can’t actually swim….
Safety guy with air tanks wouldn’t save anyone, due to pressure relief stops you need a lot of time to get to the surface with air tanks, the only way to help a free diver having troubles is to bring him to the surface quickly thanks to safety guys holding their breath… stop acting smart if you don’t know shit about the sport, freediving and security issues
@@adrienpubgm Correct
@@adrienpubgm he still has a point. You are equally vulnerable as the person who can save you. Insanely dangerous sport
@@cottoncandyflossful Yes, but I'm sure they are aware of that
"Looks dangerous" need not be equivalent to "is dangerous". In a competition environment, freediving is extremely safe. I say this as a competitive freediver.
Please educate yourself about the sport before you make insulting claims about it.
I used Badjao Technic and I can dive alone without taking any risks. A small mistake is very dangerous never pushed your body when your brain tells you to stop. Instincts and Common Sense must be highly used in Freediving.