Underwater civilizations - WTTE Ep 54

Ep 54: Underwater Civilizations & Homo Aquaticus

There is a complex and fascinating relationship between humans and the ocean. How do people and cultures across the world know and understand the sea, whether through myths and legends, trade or fishing, exploration or entertainment?

This episode explores one particular aspect of all this: our relationship with the undersea, what lies beneath the surface of the oceans.  It is the fourth stop in a loose miniseries of literary locations: Antarctica, the desert, the forest, and now the undersea.

From early myths and legends to the naturalists of the 19th century; from the first transatlantic cables to the underwater habitats of the 1960s; from scientific attempts at a “homo aquaticus” to science fiction tales of underwater civilizations, there’s plenty to explore in the ocean depths.

Joining me on this deep dive episode is Dr Helen Rozwadowski, Professor of History and Maritime Studies at the University of Connecticut.


Helen M. Rozwadowski is a professor of History and founder the Maritime Studies program at the University of Connecticut, Avery Point.  She graduated from Williams College and received her M.A. and Ph.D. from the University of Pennsylvania in 1996.  Her teaching includes environmental history, history of science, and public history, as well as interdisciplinary maritime studies courses.

She is the author of Vast Expanses: A History of the Oceans (2018), Fathoming the Ocean: The Discovery and Exploration of the Deep Sea (2005), and numerous other publications. Her academic bio is here

You can visit her website at http://fathomingtheocean.com/

Her latest book, Vast Expanses: A History of the Oceans. Reaktion Press, Ltd., 2018. is available here.

She also has a forthcoming article on Homo aquaticus: “‘Bringing Humanity Full Circle Back into the Sea’: Homo aquaticus, Evolution, and the Ocean,” Environmental Humanities, forthcoming 2022.

Prof Rozwadowski’s book

Works & Authors Mentioned & Referenced

Herbert Nitsch, record-breaking freediver

Luca, dir. Enrico Casarosa

Ernst Haeckel

Charles Kingsley: Water-Babies, A Fairy Tale for a Land Baby

Edgar Rice Burroughs: “Caspak” trilogy

Jacques Cousteau

Ignatius L Donnelly: Atlantis: The Antediluvian World

HP Lovecraft: The Shadow Over Innsmouth

Theodore Pratt: Mr. Limpet

Arthur C. Clarke: The Deep Range

Kurt Vonnegut: Galapagos

Water World, dir. Kevin Reynolds

David Brin: Star Tide Rising

Kat Falls: Dark Life

Freediver quote from: “It’s Hard to Hate Your Body When You’re Diving 100 Feet Without Oxygen”. Chantae Reden and Kimberly Zapata. Vice.com

If you enjoy the episode and want to find out how to support the show then click here for more information.

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Looking for more on places in fiction? Then try this episode on Antartica.

More on The Shadow over Innsmouth, mentioned in the episode. This episode is on HG Lovecraft

Got a recommendation for some more underwater fiction? Leave a comment below or check out the Words To That Effect Facebook Page and the show is on Instagram too!

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Transcripts: Underwater Worlds & Homo Aquaticus

I’m Conor Reid, with Words To That Effect.

Stories of the fiction that shapes popular culture.

No Limits Freediving is an extreme sport. Using any means a diver goes as far down as possible on a single breath. 

No scuba gear or other breathing apparatus of any kind – just one big breath in and a staggering amount of focus. There is no room for error, the diver has to be as relaxed and calm as humanly possible – any panic can be fatal. 

In practice, No Limits Freediving typically involves descending with a weighted sled before inflatable bags bring the diver back to the surface. Along the way the diver stops to equalize and decompress so as not to suffer the potentially fatal consequences of decompression sickness.

The world record holder is an Austrian, Herbert Nitsch, the first person in history to dive more than 200 metres on a single breath of air. He has dived to 253 metres (830 feet). That’s the height of a 60-story skyscraper – taller than all but a handful of the tallest buildings in Europe. 

He can hold his breath for over 9 minutes, and holds multiple world records across the full range of freediving events. All of this has earned him the title the “Deepest Man on Earth”. 

He and many other freedivers have continued to push far beyond what scientists had assumed were the limits of human ability underwater. And they are part, not only of a long tradition of freediving, going back thousands of years or more, but of a more fundamental connection humans have always had with what lies beneath the surface of the ocean. 

I’m Helen Rozwadowski. I’m a Professor of History and Maritime Studies at the University of Connecticut. And I study ocean history. 

I started out as a historian of Oceanography, Ocean Sciences, as a historian of science. And what I realized was that I was studying how people came to know the ocean. And I began to realize that it would be interesting and important to think about how people, in addition to scientists, came to know about the ocean

Prof Rozwadowksi researches our complex and fascinating relationship with the ocean, how people and cultures across the world know and understand the sea, whether through myths and legends, through trade or fishing, exploration or entertainment. 

This episode is going to explore one particular aspect of all this – our relationship with the undersea, what lies beneath the surface of the oceans.  

And it is the 4th place in my loose miniseries of literary locations: Antarctica, the desert, the forest, and the undersea.

The other week I watched the latest Pixar film with my kids – Luca. Not Pixar’s greatest work but a fun and imaginative film. 

Luca is a sea monster living below the surface of the water near the Italian town of Portorosso. What his parents haven’t told him, and what he soon discovers with the help of a new friend, is that he, and all sea monsters, turn into humans as soon as they leave the water. So, Luca sets off on an adventure of self-discovery all the while trying not to get wet and raise the suspicions of the sea monster-hunting Portorosso locals.

The set up of this story follows in a long tradition of human / sea-creature hybrids. In Celtic mythology, for example – here in Ireland and elsewhere – there are Selkies, creatures who can change from seal to human form. And similar mythological creatures exist across the world. Most famously, of course, mermaids and merfolk have long become a mainstay of popular culture. 

And these myths and tales all connect to the ancient and widespread conception that humans, despite living on land, have a fundamental connection to the sea: 

In Oceania, a lot of cultures in Oceania have stories about having come to the island that they live on from the west, so from the ocean, but from the western direction. There are great lakes in the United States stories about creation myths that happen with undifferentiated water and then a turtle kind of coming out and bringing up dirt and creating sort of land so there are examples of creation stories that really suggests some kind of awareness that that oceans were first which they were

Alongside a long history of creation myths in religion and folklore, there are also the scientific explanations of human origins, which began emerging more systematically in the 19th century, most famously with Charles Darwin’s theories.  

As scientists were exploring and categorising the natural world, and proposing theories of evolutionary development and human origins, the ocean depths were also being explored. The colonial powers of the time began extensively mapping the oceans for scientific, commercial, and military purposes – and these three categories are always closely intertwined in this period. 

The ocean depths, many naturalists of the time believed, could hold any number of answers to the questions they were asking – how had marine life, and all life evolved? Could there even be life beyond certain depths in the ocean? And if so, what could it tell us? 

Initially, all these questions could only be answered at fairly shallow depths. In the mid-19th century naturalists would go out on rowboats and use modified oyster dredges to catch whatever was possible a few fathoms down. Fathoms. I did not know how much a fathom was before doing this episode:

a fathom is six feet, which is the wingspan of an adult man, because sailors would measure the depth of Oceans by throwing a weighted line into the water. And then when the weight hit the bottom, they would grab an arm’s length worth of rope and count one fathom two fathom three fathoms that works if you’re just measuring the depth and a few fathoms. Sorry, that’s a little bit of a side but yeah,

Oh, this show is all about the asides.

So once naturalists started being able to sample marine life in, you know, 50 fathoms, 100 fathoms, they started discovering species, like crinoids, certain species of stock crinoids that were unknown, alive, but we’re known as fossils. And so there came to be this idea that the deep sea was the place where all of the missing animals lived, because there was a sense that things shouldn’t go extinct. So if you knew something as a fossil, and you couldn’t find it living, then that was a challenge to Creationism. And so one idea was that this, that the ocean might be full of many of these missing forms of life

There was also a very influential theory of this time that “ontogeny recapitulates phylogeny”. It was developed by a German scientist Ernst Haeckel and what it stated was that embryos, as they developed (the “ontogeny” bit), went through all the same stages a species did as it evolved (“phylogeny”). So, for example, a certain fish-like aspects of human embryonic development could be seen to recall the fish ancestry of human evolutionary development.

This all may sound firstly, you know, wrong (which it was) but also extremely technical and of interest only to the scientific community of the time. But it was actually a very well-known popular concept – the phrase “ontogeny recapitulates phylogeny” would have been fairly widely understood in the 19th and into the 20th century. 

And a good example of a manifestation of that in Darwin and Haeckel’s own time is Charles Kingsley Water Babies tale. It’s this kind of moral fable about this boy who’s kind of morally backsliding, and he transforms into this gilled tiny creature water creature as a way of giving him a chance to kind of redo his own moral evolution and emerge at the other end as a good boy.

Into the 20th century it’s even the basis for an entire trilogy of Edgar Rice Burroughs’ pulp adventure tales – the Caspak series.

So in short, the undersea became a central part of evolutionary theory and of speculation about human origins and development. 


Of course, it wasn’t all naturalists looking to explore the depths of the ocean at this time. The other very important reason to reach the bottom of the sea was to lay cables.

[staticy] “Glory to God in the highest; on earth, peace and good will toward men”. 

[morse code tap tap in background]

These were the words of the first telegraph sent across the Atlantic in 1858. The connection had finally been made after several failed attempts, with one end in Newfoundland in Canada, and the other in Ireland, on Valentia Island in Kerry. It was slow – a little over 2 minutes to transmit a single character, so even a relatively short message might take several hours to send. Still, the alternative was sending a letter by ship which could take weeks, so a major improvement.

This was the beginning of transatlantic telegraphy

After that submarine telegraphy took off, including across the width of the Pacific, so learning the topography, learning what the bottom was made out of, trying to see if it would be safe to put telegraph wires at the bottom of the ocean. Maybe there were currents, maybe there were other dangers to the cable. That was a big motivation for first studying the undersea in the second half of the 19th century.


But what about people – not dredging or looking for scientific clues to human origins, not laying cables for communication – but diving underwater to explore what was there?

Generally speaking, most scientists of the 19th century were happy to send equipment into the oceans, but they were not going to go down themselves. Throughout the century, various improvements were made to diving bells and dress which allowed people to dive for salvage operations and other reasons. But these were still complex operations in bulky and restrictive gear. 

It was only after the second world war that, for the first time in history, an easy way for people to dive and stay underwater came about, with the invention of Self-Contained Underwater Breathing Apparatus: scuba.


Before we go on I wanted to take a very quick break to tell you about two things. One, is HeadStuff+. This is the last episode in this series and if you stay to the very end I have a few announcements about what’s to come next. In the meantime, though, if you’d like to support this show and everything I do then please, become a member of HeadStuff+ – it’s the support platform for all HeadStuff shows- for €5 a month or more, if you like, you can sign up and get a tonne of bonus material – not just from this show but from every single show on the network. There’s a link in the notes to this episode or head to HeadStuff – head to, too many heads, go straight to HeadStuffPodcasts.com. HeadStuffPodcasts.com.

And if you’re next question is: well, what else would you recommend on this wonderful network, you’re in luck. I would recommend Basically… with Stefanie Preissner. It’s great, it breaks down complicated topics to the basics, with the perfect guest each time – Luke O’Neill talking about coronavirus, a finance expert on your finances, a funeral director on dying, the Taoiseach on, you know, being the leader of a country. Have a listen.

So, let’s dive back in (I’m not sorry that was always going to happen. I already resisted saying this was a deep-dive episode)

So with the invention of scuba diving, you have two things emerging: a new, easy and relatively accessibly way to dive underwater, and an emerging belief that perhaps humans could do more than just dive below the surface for a few hours. Perhaps they could live under the sea.

[“under the sea” tune]

Yeah that was always going to happen too.


The person who invented the first practical scuba gear is Jacques Cousteau. He was in the French Navy. He had been a pilot. He became very interested in in underwater swimming.

Some people who know him from his underwater environmentalist TV shows from the 1970s may think of him more as a scientist, and certainly think of him as an environmentalist. But he was really a technology enthusiast, and he started his underwater exploits. Not at all being an environmentalist he began to build underwater habitats where divers could live and work underwater for periods of time in the 1960s. And the reason he did that was because it was believed that human underwater workers would be required for the emerging offshore oil industry and for other expected mostly extractive uses of the ocean, industrial uses, agricultural uses of the ocean.

Cousteau ran the Con Shelf 1 experiment in 1962, where a group of “oceanauts” (as they were called) lived in an underwater habitat 10 metres below the surface. There were lots of these underwater habitat experiments across the 60s at different depths and for different lengths of time. In France, Cousteau ran ConShelf I, II and III. In the US there were various iterations of Sealab (not to be confused with SeaLab 2021 that brilliantly weird Adult Swim cartoon. All of this also brough back memories of that 90s TV show SeaQuest DSV with a kind of a talking dolphin. But I’m really getting off track here).

Anyway, underwater habitats were big in the 1960s. And out of this came Jacques Cousteau’s concept of Homo Aquaticus, an idea which brings us back to evolutionary theory and all those myths of underwater civilisations, AND an idea which would influence a whole swathe of pop culture stories, and science fiction in particular. 

So Cousteau, originally believed that Homo Aquaticus would need to be…involve a surgical intervention to implant gills in a human body so that people could breathe underwater and get rid of carbon dioxide from from their bodies. And their lungs would have to be filled with an incompressible liquid so that when they went down to the depths their empty cavities like lungs wouldn’t just simply collapse. 

But he believed or he asserted that he believed that after people had lived underwater for a generation or more somehow, which he didn’t really explain in any great detail, that conscious evolution directed by human intelligence would cause there to be a more permanent biological evolution, more permanent change. And, many, most of the Homo Aquaticus ideas from the 1960s onward, similarly made this move that Cousteau did where he mingled or conflated evolution and technology to come up with these various versions of ideas of people, underwater, human bodies underwater.

And while Cousteau might have been sketchy on the details, there very much were experiments happening at this time to test the human capacity to live and breathe underwater.

There were people doing physiological experiments, trying to flood the lungs of mammals. They started with mice and dogs. But eventually, one researcher found a very brave human volunteer, a former Sea Lab diver who had his lung, one lung, flooded with an oxygen risk rich liquid and he was able to breathe oxygen directly from this supersaturated with oxygen liquid. So there were a wide variety of efforts to try in the 1960s and 70s, to try to kind of make Homo Aquaticus happen.

And so all of this, as you can imagine, made for some great inspiration for science fiction and other stories of underwater worlds and human/fish hybrid people. 

There had, of course, long been a tradition of underwater civilisations, the most well-known being Atlantis – in its most recent cinema iteration, home of DC’s Aquaman, but originally made famous through Ignatius L Donnelly’s very influential 1882 classic Atlantis: The Antediluvian World

Another example, pre WWII, is HP Lovecraft’s 1931 story, The Shadow Over Innsmouth (which you can hear more about on the WTTE episode on Weird Fiction – episode 14). 

one of my absolute favorite stories that I found in researching this kind of Homo Aquaticus idea came from 1942, so before World War Two before scuba was This American novelist named Theodore Pratt wrote a book called Mr. Limpet, which in 1963, was made into a popular Warner Brothers movie called The Incredible Mr. Limpet. 

So in fact, right at the time that Homo Aquaticus was kind of hitting the newsstands, people could have had access to watch this movie, and they did. But the book in particular, dwells on fears of an evolutionary dead end that has brought humanity to World War Two. And that the idea that the way out the do over was going to be by having humanity replay evolution starting from a human being moving backward to a fish stage and intelligent fish. And that person – Mr. Limpet – was going to be responsible for the new evolutionary journey of humanity to you know, a better place, I guess. And I just think that that story is so interesting because it has the evolution component, and it is, you know, a story that was entirely made before scuba technology

From the 1960s onwards there were lots of stories inspired by developments in underwater exploration. Just as strange, deep water sea creatures have inspired the creation of many science fiction aliens, the depths of the ocean had clear parallels with the vastness of space. The 1960s saw exploration in both of these unknown and uncharted areas. Still today, the vast majority of the ocean is unmapped and unexplored – about 80% of it, in fact. 

Typical of this overlap between space and ocean is Arthur C Clarke.

Renowned as a science fiction writer, and most famous for 2001: A Space Odyssey, he was obsessed with scuba diving:

And he wrote this amazing novel called The Deep Range, which tells the story of a future Earth in a time period when people live on all kinds of planets and spacefaring is really the most prestigious thing someone can do. But this future Earth produces food in the oceans by dividing the oceans up into areas where whales are ranched for meat, and areas where plankton are farmed for harvest. So you think of – and The Deep Range is meant to evoke very clearly the American west of the 19th century with ranching and with wheat farming. And this is a story of a failed Spaceman sent to Earth to learn how to ranch whales. And this, this character gains an appreciation for the power of the ocean, which he comes to realize, in some ways, is better than space in the sense that it has lots of resources. And in some ways, he finds it to be more mysterious and harder to understand and control than space. But in the end, he comes to believe that space is a better frontier because of its endlessness. So it’s this really interesting story that looks at the oceans as a space that’s very similar to outer space in many, many ways. But is somehow in the end different

Just as with space exploration, the framing of the ocean as a frontier brings with it conceptions of exploration, invasion, and exploitation. There was seemingly unlimited wealth in this new territory opened up to humans, whether through fishing or the extraction of gas and oil. 

New thinking on environmentalism may have taken off from 1960s and 70s, about our impact on the planet and the limits of what can be produced on land without destroying it. But this kind of thinking did not apply to the oceans until much, much later:

I think one of the first things that really finally started changing that idea of the ocean being this, this kind of endless sink and endless source of resources was the crash of the Northwest Atlantic cod fishery, the 500-year-old fishery that had provided fish for the world for so for such big parts of the world. Cod fish that fed slave populations in the Caribbean, fish that was sent to Europe for all of the Catholics who needed to eat fish on on religious holidays, and to make up for the fact that the fisheries in Europe were declining. Long story short, in 1992, Canada closed the Northwest cod fishery, and everyone expected that in 10 years, without the fishing pressure on the stock, it would rebound, and it didn’t. So it wasn’t even, I would argue the closure of the fishery. But it was the really unfathomable experience of seeing that it didn’t rebound as everyone expected that it would, after it was left alone. And it took probably another decade or more after that, for scientists to understand that what had happened wasn’t just removing a certain number of fish that were a good economic resource, but that in fact, the scale of fishing of that cod stock had changed an entire ecosystem

Increased awareness of climate change has meant the oceans and the deep sea are a central part of environmental awareness. And of literature and pop culture too: 

In the 80s there’s even more examples of this. Some of my favorites are Kurt Vonnegut’s Galapagos, which is a story that humans evolving to be sea creatures. It’s a pretty fascinating story. Kevin Costner’s Waterworld is very clearly about sea level rise. For sci fi fans, there’s this great book by David Brin called Star Tide Rising the story of humans and chimpanzees, uplifting dolphins to sentience and space travel. And I love that because you see that the different species need different kinds of prostheses, depending on whether the action is in a wet place, or a dry place. So you have these really interesting combinations. 

But then if you look today you see young adult literature like Kat Falls Dark Life and the sequel Riptide which posits these biological changes that happened to the first generations of children born in their benthic settlements. Sounds a lot like Jacques Cousteau, kind of easy assumption that once people live underwater, they’ll just change.


Which brings us back to freediving. Our bodies can adapt and be trained to dive for long periods underwater. And many divers feel a connection with the water they just can’t experience on land. According to one freediver: 

“On every dive, it’s critical for me to be hyper-aware of my body: position, movement, oxygen level, and the depth of the water around me. I am surrounded by blue, split by rays of sunlight dappling between plankton particles. Within seconds of submerging underwater, my body experiences what’s known as the mammalian dive reflex, which causes the heart rate to slow and blood from the limbs to shunt to the torso, enriching vital organs with oxygen. At some point, I become weightless, suspended as if I were floating in space. Tension leaves my muscles. After this, my body becomes negatively buoyant and freefalls towards the ocean floor. It feels like I’m flying”.

We can’t live underwater but we can learn to appreciate it, to find calm and joy within its confines, to learn from the cultures that have generations of experience diving to the ocean depths. And we can certainly try not to destroy it. The ocean can’t be treated a frontier to be depleted and destroyed, but it can be an inexhaustible source of inspiration for scientific discovery, myths and legends, and some great science fiction.


That’s it, thanks so much for listening. A huge thank you to my guest this week, Prof Helen Rozwadowski. You can check out more on her website FathomingTheOcean.com or pick up her book Vast Expanses: A History of the Oceans. I’ll put links to these and her other work on the WTTE website, wttepodcast.com

And that is the end of Season 5. As you may have noticed this past season was nowhere close to being released fortnightly, as previous seasons have mostly managed to be. Lockdowns, closed schools, working from home and everything else did not make for a good podcast schedule.

So, I am going to use this season break to have a think about how I can make the show sustainable in the longer term, cos I really, really like making it but right now it’s killing me.

So, firstly thank you to those who filled out the listener survey, that is going to help a lot in thinking about the show. And of course thank you to all the HeadStuff+ and other supporters who have been so generous with monthly donations. That money is all going to go back into the show to help grow it and help out with quite a few areas.

So, stay tuned. I’m going to make a few changes, there may even be a refresh of the artwork, and I’m going to start working on some new bonus episodes too for all you supporters. And you can become one too at HeadStuffPodcasts.com

I’ll keep the website updated, wttepodcast.com, and you can follow the show on Instagram and facebook @wordstothateffect, and I’m on twitter @cedreid

So for now, thank you, if you’re a new listener or you’ve been here for 54 episodes over 4 years.

I’ll see you soon for Season 6.

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