 So, I bet you're all wondering what a guy who just wrote a book about freediving is doing speaking at a float conference here. I was wondering the same thing when I was asked to speak here a couple of months ago by the organizers. I've been floating for about five or six years, but I didn't ever really think about the connection between floating and freediving. So I spent a few days researching and found that there was a tremendous amount of overlap between these two activities. Many of the same physiological changes that occur in the float tank also occur when we dive in the ocean, only more so, and the deeper we dive, the more pronounced these changes within us become. In many ways, freediving is like floating on steroids. It's a much more pronounced thing that happens. So most of you, actually all of you here, are familiar with what happens to the body in the float tank. The heart rate lowers, breath rate lowers, your body starts consuming far less oxygen, brain waves soften, muscles relax, blood starts flowing through your tissues more easily, your metabolism slows, you feel mellow, you feel great. These changes that occur within us aren't provoked by the darkness or isolation of the tank. They're provoked by the water within it, and these changes can be sparked in any massive water, be it in a bathtub, in a float tank, in a lake, in the ocean, whatever. The deeper we dive, if we choose to dive deeply, the more profound this transformation becomes, and it becomes so extreme that at very deep depths, our bodies bear only a passing resemblance to our terrestrial forms. The water will physically change us. This call, this transformation, the mammalian dive reflex, or more lyrically, the master switch of life, and they've been researching it for about 50 years. The term master switch of life describes not one, but many switches, and these reflexes that affect our brain, our lungs, our heart, they all work in contact with other triggers in the body to protect us from the immense pressure of a deep dive. They turn us into efficient deep sea diving animals. Ancient cultures knew all about the master switch and employed it for centuries to harvest sponges, coral, pearls, and food hundreds of feet below the ocean surface. Ancient sailors in the 1700s reported seeing pearl divers dive down to about 150 feet, and according to their records, stay down there for 15 minutes at a time on a single breath. Now, that sounds totally impossible, I realize, and most scientists that heard these reports didn't believe them. They said they were fabricated or exaggerations. Up until the 1950s, scientists said that the deepest a human could dive and survive was 100 feet. Any deeper than that, and our lungs would collapse when we'd die. Since then, modern freedivers have dived down to more than 700 feet on a single breath of air. The latest world record in breath hold was 12 minutes and 30 seconds. So that's just two and a half minutes short of these fabricated reports from these ancient sailors. If we keep going at this rate, competitive freediving is a very new sport. We're going to surpass 1,000 feet and be able to hold our breath for more than 15 minutes in probably five or 10 years. So how is this possible? How can our bodies survive in stresses that are 30 times that of the surface? In water, the deeper we go, the more pressure increases and the more air contracts. Sea water is 800 times denser than air, so this pressure increase happens very quickly. A dive down to just 10 feet is equivalent to diving down 10,000 feet in the atmosphere. And instead of bags of chips puffing up like they do on an airplane or on a drive up to the mountains, anything with a flexible surface and air inside it in the water will shrink down the deeper it goes. Human lungs, for instance, will shrink down to half their size at just 30 feet. They'll shrink down to a third of their size at 66 feet, a quarter of their size at 99 feet, and so on. You can imagine this place hell on the body. The equivalent pressures of these deep dives down to around 300 feet would kill or injure us on land, but not in the water. To combat these stresses and keep us alive during deep dives, our bodies spur one of the most extreme transformations we can naturally experience. That's the master switch of life. We're born of the sea, and each of us has an ocean within us. Human blood holds about a 98% similar chemical composition to sea water. The amniotic fluid in which a fetus develops is about 99% similar to sea water. The first characteristics of our fish-like in the human fetus, we grow fins first instead of feet or hands and are one misfiring gene away from growing fins instead of feet or hands later on. So we're also born to dive. The human infant, when placed in water, can comfortably hold her breath for about 45 seconds at a time, will instinctively start breast-stroking and open her eyes. We only lose this ability when we learn how to walk. But regaining it is easy. Our bodies already know how to do this. You just take a breath and go and let your body do the rest. So what I'm going to do now is explain these things called the master switch of life, these various reflexes. You'll notice that many of the same physiological reactions are very similar to the float tank, what happens to the body in a float tank, but again, they're much more pronounced. The clip I'm going to show is of a French diver named Jeremy Neary. It's been viewed about 25 million times on YouTube. He's going to be diving down to around 300 feet and I'll explain what is happening to him along the way. It's important to note also, Neary isn't really special. Each of us are imbued with these reflexes. We're born with these abilities. Anyone here, almost anyone here, if you really wanted to dive down to 100 feet with a little bit of training, you'd be able to do it. Some of you can make it down to 200, even 300 feet. I've been to competitions and seen numerous people from all over the world. Small people, tall people, fat people, skinny people, it doesn't matter. They were all diving extremely deep. We're built to do this. So I will start the clip here. So the second Neary's face is going to touch the water, something amazing is going to happen. His heart rate is going to slow about 25%. Blood is going to start rushing from his extremities into his core and he's going to enter a meditative state. His brainwaves are going to soften. At around 35 feet, something else amazing happens. Buoyancy reverses. If you swim in a swimming pool, you're going to dive down and your buoyancy is going to bring you back up to the surface. That all changes at 35 feet. It's an area that freedivers call the doorway to the deep. Past that depth, you start getting sucked down by the water and you'll keep falling until you hit the sea floor. You'll notice he's wearing a weight now. That's just to hold him to the sea floor at around 30 feet, but he's going to jump here in a second and he's not going to kick, he's not going to move his arms, he's just going to fall effortlessly down. He will continue falling in this way as deep as he wants to go. At around 150 feet, his lungs will shrink to the size of two-fifths. To combat these stresses, his heart rate will lower even more than it just had at the surface. Freedivers have recorded heart rates as low as 14 beats per minute. That's about a third of the rate of a coma patient. Some freedivers, this is true, have recorded heart rates as low as seven beats per minute. According to our understanding of the human body, physiologists say this is absolutely impossible. A heart rate that low cannot support consciousness, and yet these guys do it all the time and they don't really care what the physiologists are saying. At around 300 feet, his chest is going to start shrinking to about half its size. The freediver had a chest circumference of 50 inches at the surface at 400 feet, it was 20 inches. The master switch really goes into overdrive here. The alveoli and the lungs begin engorging with blood. Water and plasma start seeping into the thoracic cavity to protect the organs from crushing. The spleen releases about 15% new oxygenated blood into the body, which allows these guys to dive deeper for longer. Once we hit the sea floor here, now comes the really hard part. He needs to make it back up, pushing against 300 feet of water. Remember, the buoyancy is reversed, but he's a very experienced guy. He's even doing a little air guitar in here. He's taking his time because he knows to conserve about 60% of his oxygen for the trip back up. In that regard, it's much like mountain climbing. He's going to push against his buoyancy here. He can crawl. You can do whatever you want here. There's zero gravity. You can just have a good time. As he is continuing to ascend, all of those master switches within him reverse. His heart rate begins beating more quickly. Blood starts flushing back into his limbs. His mind wakes up. He starts to resemble his terrestrial form. Freedivers cannot get the bends. That only happens with scuba. Our bodies naturally know how to process the exchange of gas and purge all the nitrogen from the body. You'll notice he's going to expel all of his air about 10 feet before the surface. That's going to relieve the pressure. He's going to get up, take a deep breath, and get prepared to do it again. So that is the master switch of life. Thank you. Okay. We're not the only ones born with the master switch of life. Seals have it. Dolphins have it. Whales have it. And they are much more adept at using it than we are. These guys, wettel seals, can hold their breath for over an hour and dive down to 2,500 feet. Again, scientists who have studied these animals, they calculated the oxygen in their blood and they seem to gain oxygen the deeper they dive. Well, that doesn't make any sense, according to our understanding of physics and mammal physiology. But again, these seals don't really care what we think they do it all the time. They've been doing it for millions of years. It just kind of shows you the potential of these animals that we just don't even understand yet in our own potential as well. But the real masters of the master switch are sperm whales. These animals can dive down 9,000 feet and they can hold their breath for about an hour. Now the pressure down at 9,000 feet is 280 times that of the surface. So their master switches really kick into overdrive. Their heart rates lower extremely to extremely low rates like I think it's a tenth of the rate at the surface. They tremendous amount of blood shifts into their cores and all these things are the same things that happen to humans in a float tank and also humans when we free dive. That's the only way they'd be able to make these dives is through this master switch. And something amazing happens when you free dive with these animals is they notice you're different than the other oceanic animals. They notice that you too have the master switch. I know that sounds crazy but I'm going to show you a video here in a second that kind of proves it. And a real paradigm shift occurs and instead of swimming away from us they approach us. So scuba gear doesn't work when you're studying sperm whales and robots can't get close to them and submarines can't get close to them because all of those machines are very, very loud and disturbs their sensitive hearing. But when you free dive with them in your natural form they approach you, they welcome you into the pod and they have stayed with free divers for four or five hours at a time just hanging out trying to study us as we're studying them. So the real power of the master switch and being able to free dive and get in the water is to be able to connect with these animals in this way and really study them up close. And now I'll give you a little view of this whole paradigm shift in action if no one believes me. What you're about to see is a bunch of free divers they're studying the sperm whale click communication diving with whales and filming them and recording with some very sensitive audio equipment. Now you're going to hear a bunch of clicks and hopefully the audio is working here. Those clicks aren't coming from a boat and they're not coming from scuba or any of the free divers. They're coming from the sperm whales. Sperm whales use something called echolocation which is a very sophisticated form of sonar and the sonar is so sensitive that a sperm whale can see you from a mile away. It can be underneath you a mile away and see you. And these clicks are the loudest things that any animal can make on the planet. They're 236 decibels loud which is really, really loud. Some researchers think that sperm whales can stay in contact with one another across the globe and they use the deep depths which propagates noise much easier than the surface to stay in contact with one another. So I'll just show you a little bit of this. These clicks again are so powerful that they penetrate through the flesh and sperm whales can actually see into you. That's why free divers believe that they don't eat us because they can see we have big brains, we have lungs, we're different than other animals. So this is what happens when a sperm whale starts giving you an x-ray which is essentially what it is. I'll just be quiet here and let you guys soak into this. So the whale is going to turn around on its belly. They don't listen with ears, they listen with the fatty sac underneath their jaws and they can hear in all directions at once. So he's taking a really good look at this guy to make sure he's not food. And these clicks are so powerful that this researcher a little later on put his hand out to its nose to stop the whale from bumping into him and his hand was paralyzed for about four hours because its nose was shaking so violently. So that brings up a question. Why would anyone want to do this? Why do you want to free dive with an animal that has eight inch long teeth that is the world's largest predator that usually snacks on 60 foot long giant squid that could easily eat us? I mean without even thinking about it these animals could destroy us. Why would we want to get this close? Well, what we've discovered in the last decade or two is that those clicks that you are hearing aren't just used for echolocation. They have a whole set of different clicks that are used for communication. And inside of these clicks is probably one of the most sophisticated languages around. And I know that sounds completely insane. Maybe to this audience I don't have to explain to you who John Lilly is. I usually do, but I'm going to just skip that little part here. So he studied sperm well clicks, as you all know, sperm well communication for years and years and years. He considered the sperm or dolphin clicks, that is, and he considered the sperm wells the most intelligent animals that have ever been on, ever graced us with their presence on this planet. He just wasn't able to put one of these things in a lab. You can see this is a head-on picture of sperm wells. That thing on top is the brain. It's six times the size of yours. They have neocortexes, which, you know, in humans are thought to govern such functions as conscious thought, future planning and language. In the sperm well, the neocortex is estimated to be six times larger than ours. Sperm wells also have spindle cells, the long and highly developed brain structures that neurologists have associated with speech, feelings of compassion, love, suffering, intuition, all those things that make humans human and separate us from apes. Sperm wells not only have spindle cells, but they have them in a far larger concentration than we do, and they've had them for 15 million years longer than we have. It's estimated that sperm wells have had their current brain size about 40 million years. We've had ours for about 150 to 200,000 years. You can do your own math there. Why do they have such super evolved brains? They need a brain about this size to control their body. For instance, is an enormous animal 40 feet long. It's got a brain about that big, and it gets around just fine. So they have extremely evolved brains. What are sperm wells doing when they float side by side and click at each other like this? These are not echolocation clicks. These are communication clicks. This isn't a theory. This is a fact. We know they're talking. Sperm wells from different areas of the planet have different dialects. Dolphins, they have found recently not only have first names, but they have last names too. So we know these animals are communicating, but what are they saying? These are just some of the questions that this band of DIY freedivers has been trying to answer in the last couple of years, and I was lucky enough to spend the last 18 months with these guys doing some of this research and writing about the experiences in my new book, Deep. And that to me is the real amazing part of the Master Switch, is these reflexes we share with all these oceanic mammals that are triggered in the float tank as well as the ocean, not only profoundly transform our bodies, but also bring us closer to understanding the ocean, its inhabitants, and our own untapped potential. Thank you very much. That's it.