Susan Casey is an accomplished journalist who's spent years writing about the ocean, and most recently, the deep sea. The deep sea generally starts around 600 feet below the surface where you could no longer see the light from above, but it goes way beyond that. In some places, the ocean is almost seven miles deep. Susan is one of the few people who's gone deeper than 5,000 meters in a submersible, which is over three miles down to the ocean floor.
Susan Casey is an accomplished journalist who's spent years writing about the ocean, and most recently, the deep sea. The deep sea generally starts around 600 feet below the surface where you could no longer see the light from above, but it goes way beyond that. In some places, the ocean is almost seven miles deep. Susan is one of the few people who's gone deeper than 5,000 meters in a submersible, which is over three miles down to the ocean floor.
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Susan Casey:
I mean, the only thing I would say to give you a real sense of what it's like to go into the deep ocean is you feel like you're inside the heartbeat of something very, very big and very, very serene. It's just, it's zen.
Shelby Stanger:
For Susan Casey, the ocean is a place of personal, calm, surrender, and majesty, but it also contains great scientific value. Susan is an accomplished journalist who's spent years writing about the ocean, and most recently, the deep sea. The deep sea generally starts around 600 feet below the surface where you could no longer see the light from above, but it goes way beyond that. In some places, the ocean is almost seven miles deep. For the last several years, Susan has interviewed experts in deep sea exploration and reviewed the leading aquatic research. She's even one of the few people who's gone deeper than 5,000 meters in a submersible, which is over three miles down to the ocean floor. I'm Shelby Stanger, and this is Wild Ideas Worth Living, an REI Co-op Studios production.
Susan Casey:
People will kind of say, okay, we live on an ocean planet, but here's the extent of how much we live on an ocean planet. If you think of the Earth as a biosphere, as a living space, 98 to 99% of it is, some people will say 99, is ocean. And of that 99%, 95% is deep ocean.
Shelby Stanger:
Susan Casey has published multiple bestselling books that explore different facets of the ocean, from sharks and dolphins to giant waves. Even before she started writing books, Susan had an impressive resume as a journalist, she was the creative director of Outside Magazine, the editor at large for Time Inc's magazine titles, and the editor in chief of Sports Illustrated Women and O, the Oprah Magazine. Now, after six years of research, interviews and reporting, Susan has written a new book called The Underworld: Journeys to the Depths of the Ocean. Susan Casey, welcome to Wild Ideas Worth Living.
Susan Casey:
Thanks, Shelby.
Shelby Stanger:
I've been following your career for a while, and I have to say there's a few women that I've looked up to in my career, female journalists who cover adventure, and you're one of them.
Susan Casey:
Thank you. Yeah, I appreciate that.
Shelby Stanger:
I'm curious how your love of the ocean developed. You're from Canada, and a part where you didn't have an ocean right in front of your house.
Susan Casey:
I've asked this question of myself so many times because I'm curious to know the answer. Yeah, I grew up in Toronto, in suburban Toronto. There were lakes north of my house where I grew up, but I think that my love of the ocean actually was just sort of baked in when I was born. I don't ever recall developing it. What particularly I remember is if I would see a swimming pool that was illuminated at night, it was hypnotic. I couldn't not go towards it or look at it, want to get into it. Which led to a career as a competitive swimmer, an open water swimmer, but it was a while before I got around to spending time in the ocean.
Shelby Stanger:
You like open water swimming. How did you get into that?
Susan Casey:
Well, I swam competitively from age 10 and swam through university at the University of Arizona. And yeah, and after that I did triathlons for a while, but realized, like most swimmers, that biking was fine, but running was not. And started really loving open water swimming, and had swam in lakes as a kid and that. And so I was invited to do a couple long distance races in Hawaii. And at the time, I mean back in the day, we trained, we were so overtrained, I was really trained for a six mile long distance swim, even though I was a 200 breaststroker. And so I started doing these open water swims, and realized that was really what I loved. But I was scared of fish, I was scared of waves, I was scared of the ocean. It took a while for me to sort of lose my fear and really start looking around myself and going, oh wow.
Shelby Stanger:
Over the course of her career as a journalist, Susan wrote articles about sea life, surfers, and marine biology. In 2010, she came out with her first book about a story between sharks and surfers in California. For her latest book, Susan dove deep literally, learning everything she could about the mostly undiscovered world at the bottom of the ocean.
One of the coolest parts of her reporting included exploring the sea floor in a submersible. You might've heard about the tragedy of the Titan sub that imploded in June of 2023, but Susan says most submersible trips are very safe. Everybody heard the news about the submersible that imploded, just totally tragic, and I'm sure you have a lot of thoughts on it. But in your book, you had to go into one of these submersibles. So first, can you just talk to me about what is a submersible?
Susan Casey:
Yeah. So people think of undersea vehicles, often they will think of submarines, which are completely independent. They have their own air supply. They can stay down for a long time. They don't go particularly deep. I don't know what the maximum depth is because it's information the US Navy doesn't release, but it's not that deep. And maybe 400 to 600 feet max. But submersibles are able to go much, much deeper.
And one of the submersibles that I dove in was certified to dive to the full depths of the ocean. So down to 36,000 feet. It is the only one of its kind. Actually, when I started the book, it was just being completed, and it was the only one of its kind right until I was writing the epilogue after which China dove successfully in a three man full ocean depth science submersible. So there are two now that have ever existed that can dive repeatedly to full ocean depth. So very few.
And the other thing about a submersible is that it can fly around independently beneath the surface, but it's powered by batteries. So it doesn't have the kind of ability to stay under water for extended periods of time the way a submarine does. It needs a ship, it needs a launch system, it needs people launching it. It needs people recovering it. So it has a mothership attached with it.
Shelby Stanger:
Very few people have actually been able to be in a submersible. They're expensive. And it's either you have to have a lot of money, and just kind of like going to space right now, you have to have an absurd amount of money, or you have to have some sort of privilege, either being a really cool journalist like you, or being part of the Navy, or something like that. I still can't imagine what it's like to be in one. Can you tell me what it was like? How big is it? What are you inside of? What are you eating? How long do you go for? Because you did it in your book.
Susan Casey:
Okay. Well, without giving away anything from the book, I was in more than one, several. And typically, if you have claustrophobia, you might not enjoy it so much. But there are certain submersibles that go to around 3,300 feet. They're making that range a little bigger now, but they have an acrylic pressure hull. So you're sitting in this really cool bubble, very thick acrylic, very crystal clear. I don't know if a claustrophobic person could tolerate that, but you might have a better chance of tolerating that.
But the submersible that dove to the full ocean depth was a five foot diameter titanium sphere, three and a half inches of titanium. It was machined so that it was perfect. So there is no area of vulnerability. Because at the very bottom of the ocean, it's eight tons of pressure per square inch. So you cannot have a tin can down there. You have to have this perfect sphere. And it's just incredibly secure. And you have oxygen bottles lined above your head.
And there's two people, me and the pilot. And you sit in sort of tightly body fitting seats with your knees sort of touching. And there's enough room for me, as a fairly small person, to be snug, but not insanely snug. But for a large man, it's an interesting day. And you're down there for the whole day. I mean, for one of my dives, it took us almost three hours to get to the bottom of just free falling. And then it takes about the same time to come back up. They're very sophisticated machines. When you're sitting in them, you're in awe of the engineering that has gone into them.
What happened with the Titan submersible is something that was well known in the very small, tight-knit world of manned submersibles for a very long time, certainly since I started reporting back in 2018, was that the owner and creator of that sub, he had just ignored all the safety rules, and all the many, many layers of knowledge that have accrued over the years. There hasn't been a sub implosion ever until this. There has not been a fatality in a submersible in 50 years. They are actually the safest mode of transportation, and they operate in the riskiest environment in the world.
So everybody who goes down in one is aware that the number one thing that you have to take is this respect for the deep ocean and its forces, and he did not have that. We're going to be seeing a lot of information coming out in investigations and stuff that will show the real extent of how much he disregarded those safety regulations. It's just physics. It doesn't matter. The deep doesn't care if you have an aerospace degree from Princeton. The deep doesn't care what you think about what might work.
When you go down there, it's her rules. Her rules are actually well-known. The materials that all other submersibles are made of are very predictable, how they will respond to pressure. They've been tested and tested and tested and refined and tested. And it's not that nobody can innovate, it's just that every time you innovate, you introduce uncertainty into a realm that doesn't abide any slip-ups when it comes to us going there.
And one of the things I love about the deep ocean is that, like space, I think we're so interested in space because when we rocket up there, we're conquering something. We're expanding our reach. To go into the deep ocean is a journey inward that you submit to. It's surrender. We are not in charge down there. We go there, but only according to her rules. But one thing that I think is really important to mention is you don't have to dive into the abyss. You can go snorkeling and see another world. And the thing about the ocean that I love so much is I always say enchantment is always available underwater. I often don't think it's always available on land.
Shelby Stanger:
That's so interesting. Snorkeling, it feels like nothing else. I feel like my heart rate slows down. I just feel like I did like 10 hours of yoga if I go snorkeling.
Susan Casey:
I mean, the only thing I would say to give you a real sense of what it's like to go into the deep ocean is magnify that feeling times 1,000. You feel this calmness, this zenness, because time is gone. Time goes very elastic. You can't tell. And absolutely everybody who has ever been in a submersible has said this. You don't know whether you're down there for an hour or six hours. And it's because there's no signposts. There's no anything, there's no horizon, there's nothing. You feel like you're inside the heart beat of something very, very big and very, very serene. It's just, it's zen. It's like almost even if I watch a camera going into the deep ocean, I feel my whole body relaxing. And it's like exactly the feeling that you were talking about, but it gets really profound, which means deep.
Shelby Stanger:
That's amazing. Okay, so let's go back to the first time you were in a submersible. Where did you take off from and what was it like?
Susan Casey:
They often do dives in The Bahamas because you can get to deep water, it's clear, it's beautiful, fairly easily. And so we made it through this very luminous, sort of trippy, vibrating blue. It just kind of goes right through your body. It feels like it's alive. And everybody just kind of freaks out when they experience it. And then we started going through a slightly more indigo version where there's still blue light, but the sunlight has started to diminish a lot.
And then you're into the darkness, and around 700 feet you start seeing bioluminescence. And you realize in the twilight zone that, unlike space, we're floating and drifting and descending through a matrix of life. It is so extensive. It is just everywhere. And it's microscopic, it's microorganisms, it's tiny fish, it's larger jellyfish. The majority of all known jellyfish species live in this band of ocean. So you see a lot of creatures that look like UFOs, flashing lights. And we got down to the bottom, and they turned on the lights, and it was like I had no idea that it was going to be so beautiful. It took my breath away. It was unexpected.
Shelby Stanger:
When we come back, Susan talks about how deep sea mining threatens to hurt our environment and hinders possible scientific discoveries. She also talks about overcoming her fears and the power of surrender.
In her new book, The Underworld, journalist Susan Casey documents her trips to the deep sea and leads readers through the latest oceanic research. With the help of new technology, scientists can take photos of rare aquatic life and monitor underwater volcanoes. Experts have also discovered unique resources beneath the ocean floor, like metals and materials that can be used to make electric car batteries, solar panels, robotics, and more. But to harvest those materials, companies have to mine the ocean floor. Susan says this deep sea mining could have a massively destructive impact on humanity and the environment.
I thought it was really interesting that you talk about that the deep is a really key metric to the future of our planet. And I'm curious how that's such a great metric and how it's going to help shape our science for climate change and climate conservation.
Susan Casey:
For sure. I mean, it's 95% of the planet, it's the machinery that runs the climate system. And we don't know enough about it yet, but it's very urgent that we sort of deepen our relationship with the deep ocean. Because it's quite unreasonable to think that here we are up in the air on our 2% of the planet, and it's just separate from us and we can ignore it. I mean, this is a time of dramatic change. And in order to be able to survive through these what will be upheavals, what will be changes, shifts, perhaps extremely dramatic ones, we are going to have to understand how the whole system works, and it's incredibly complex.
Shelby Stanger:
So you've also learned some of the threats to our ocean environment in doing this book, including deep sea mining. Can you just talk to us about what that even is and give us some background?
Susan Casey:
Yes. I want to talk about deep sea mining at every possible occasion. Because deep sea mining is basically, it happens at abyssal depth, so it happens pretty deep in the ocean, down two and three miles. And there's parts of the ocean where these nodules form that are made of metals, and they have cobalt, nickel, manganese, and various other things in them. This is not the only form of deep sea mining, but this unbelievable threat to the health of the Earth, the resilience of the Earth, it is the most hubristic and unwise thing that I can imagine us doing, although there's probably others.
But this one is huge because every mine site is 30,000 square miles. And when they come along to take those nodules, they're also taking the sediment beneath them. And the sediment down there is alive, right? There is microbial life that goes beneath the sea floor up to a mile. And it's incredibly ancient. We don't know much about it. They call it the deep biosphere. And some of the microbes are 100 million years old, who knows, maybe there are even older microbes. They have learned to live through all kinds of different situations, different conditions, really hostile conditions. And so they have developed mechanisms that can teach us things about resilience.
So there's a whole lot that we can learn about, say, future medicines, bio compounds. They have found a microbe that has given them a compound that kills glioblastoma cells, which is the cancer that killed John McCain. There was no cure for it. It's in trials now, and it was from deep sea sediments. And this is just the beginning of this research. And we have problems like antibiotic resistant strains of bacteria. That's where our answers are going to come from, is this sediment and creatures in the deep ocean.
And they live in the nodules, on the nodules, under the nodules. And there are companies that want to scoop these up so that they can use the cobalt and the nickel mainly to make EV batteries, solar cells, things like that. And they will all be sucked up a pipe, and we will lose things that we never got to know in the first place. So many, many deep sea scientists have signed a moratorium request, demand, plea. It's a primal screen basically. We can't start this. If we do it at all, we need at least 10 to 30 years more study.
And it doesn't appear that that is going to happen, although I just want to talk about it at every occasion so that everybody knows about it, because I think people don't realize this is imminent. And I honestly feel if we do this, we will have failed a sort of wisdom test that I don't know how you come back from that. It's the biggest carbon sink on the planet. And the idea that we would be crazy enough to reach down three miles into the earth's womb, this part of the ocean largely untouched by us. I mean, it's got nanoplastics and things like that. It's got pollution that has filtered down, but we haven't been down there. We haven't done stuff really. Run sea floor cables, but that isn't very much. This is large scale industry that makes terrestrial mining look very small. And yeah, I'm still learning how to talk about it without freaking out.
Shelby Stanger:
A few companies like Google, BMW, and Patagonia have already committed to staying away from the minerals that are mined from the ocean floor. Because this research is fairly new, not a lot of people are aware of deep sea mining and the damage it could cause. Susan, on the other hand, spent six years interviewing scientists and devouring the latest research on the subject. Most of the time, it was fascinating work, but of course there were moments of uncertainty and even doubt along the way. Yeah, I mean, you did this for six years and you kept going. Were there any times that you were scared?
Susan Casey:
Yes. There were times when I was scared. And that's the great thing about nonfiction. You never know what's going to happen during your reporting. I actually often feel very fortunate to be a nonfiction writer because I couldn't make up half the stuff that I've seen and experienced. So yeah, you're sort of, a lot of the times it's like, well, let's just give this a try. And well, I wouldn't say there are any times in this book that I was particularly terrified. In all of my books, there have been moments when I had real trepidation about things, and thought, what am I doing here? And will this really work? And how could this ever work? And you probably have experiences too. You go through this incredible cycle of self-doubt and worry. And you just kind of have to go with the flow. But I would say I've gotten used to it, but it's always there.
Shelby Stanger:
I'm sure when you swam with sharks, you learned something really deep from that. When you explored these rogue waves, you've learned something about that. But philosophically, it sounds like exploring the depths of the ocean taught you something about this different philosophy, which is just more of this peace and surrender. I don't know.
Susan Casey:
Yeah. So when you get to that point where you're going to do something hard and you're grinding against it, there is this moment where, if you surrender, there's incredible power in surrender. Surrender is powerful. Because there's only so much you can hold up, right? When you let it go, that feeling that you get of like, okay, we've surrendered here, then you can go forward.
But as I said before when I was talking about how submersibles are built, that the ability to surrender in the deep ocean is knowing that you have acquiesced to the rules that she has set. And those rules are that when you go down there, you're going to be under crushing, crushing pressures. And if you want to come back, you have to have accommodated to her rules. So we often think that we're running this show. We run the planet, we run nature. Nope. All you have to do is look at a 70 foot wave or get 3,000 feet under the ocean to know that that is not true.
Shelby Stanger:
So many surfers, myself included, have felt and talked about the power of the ocean. But the ocean is so much deeper than I ever imagined, and there's still so much left to be discovered. If you want to learn more about the latest research from the deep sea, check out Susan Casey's new book, The Underworld: Journeys to the Depths of the Ocean. Her writing is incredible. She really makes you feel like you're right beside her on these adventures.
Susan, thank you so much for coming on Wild Ideas Worth Living. You've been a long time role model of mine, and most importantly, thank you for bringing the latest oceanic research to the public. If you want to learn more about Susan Casey, check out her website, susancasey.com. She's also on Instagram @susanlcasey. That's S-U-S-A-N-L-C-A-S-E-Y.
Wild Ideas Worth Living is part of the REI Podcast Network. It's hosted by me, Shelby Stanger, produced by Annie Fassler, Sylvia Thomas, and Sam Peers Nitzberg of Puddle Creative. And our senior producer is Jenny Barber. Our executive producers are Paolo Mottola and Joe Crosby. As always, we love it when you follow the show, rate it, and write a review wherever you listen. And remember, some of the best adventures happen when you follow your wildest ideas.