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The Underworld: Journeys to the Depths of the Ocean
From bestselling author Susan Casey, an awe-inspiring portrait of the mysterious world beneath the waves, and the men and women who seek to uncover its secrets
For all of human history, the deep ocean has been a source of wonder and terror, an unknown realm that evoked a singular, compelling question: What’s down there? Unable to answer this for centuries, people believed the deep was a sinister realm of fiendish creatures and deadly peril. But now, cutting-edge technologies allow scientists and explorers to dive miles beneath the surface, and we are beginning to understand this strange and exotic underworld: A place of soaring mountains, smoldering volcanoes, and valleys 7,000 feet deeper than Everest is high, where tectonic plates collide and separate, and extraordinary life forms operate under different rules. Far from a dark void, the deep is a vibrant realm that’s home to pink gelatinous predators and shimmering creatures a hundred feet long and ancient animals with glass skeletons and sharks that live for half a millennium—among countless other marvels.
Susan Casey is our premiere chronicler of the aquatic world. For The Underworld she traversed the globe, joining scientists and explorers on dives to the deepest places on the planet, interviewing the marine geologists, marine biologists, and oceanographers who are searching for knowledge in this vast unseen realm. She takes us on a fascinating journey through the history of deep-sea exploration, from the myths and legends of the ancient world to storied shipwrecks we can now reach on the bottom, to the first intrepid bathysphere pilots, to the scientists who are just beginning to understand the mind-blowing complexity and ecological importance of the quadrillions of creatures who live in realms long thought to be devoid of life.
Throughout this journey, she learned how vital the deep is to the future of the planet, and how urgent it is that we understand it in a time of increasing threats from climate change, industrial fishing, pollution, and the mining companies that are also exploring its depths. The Underworld is Susan Casey’s most beautiful and thrilling book yet, a gorgeous evocation of the natural world and a powerful call to arms.
For all of human history, the deep ocean has been a source of wonder and terror, an unknown realm that evoked a singular, compelling question: What’s down there? Unable to answer this for centuries, people believed the deep was a sinister realm of fiendish creatures and deadly peril. But now, cutting-edge technologies allow scientists and explorers to dive miles beneath the surface, and we are beginning to understand this strange and exotic underworld: A place of soaring mountains, smoldering volcanoes, and valleys 7,000 feet deeper than Everest is high, where tectonic plates collide and separate, and extraordinary life forms operate under different rules. Far from a dark void, the deep is a vibrant realm that’s home to pink gelatinous predators and shimmering creatures a hundred feet long and ancient animals with glass skeletons and sharks that live for half a millennium—among countless other marvels.
Susan Casey is our premiere chronicler of the aquatic world. For The Underworld she traversed the globe, joining scientists and explorers on dives to the deepest places on the planet, interviewing the marine geologists, marine biologists, and oceanographers who are searching for knowledge in this vast unseen realm. She takes us on a fascinating journey through the history of deep-sea exploration, from the myths and legends of the ancient world to storied shipwrecks we can now reach on the bottom, to the first intrepid bathysphere pilots, to the scientists who are just beginning to understand the mind-blowing complexity and ecological importance of the quadrillions of creatures who live in realms long thought to be devoid of life.
Throughout this journey, she learned how vital the deep is to the future of the planet, and how urgent it is that we understand it in a time of increasing threats from climate change, industrial fishing, pollution, and the mining companies that are also exploring its depths. The Underworld is Susan Casey’s most beautiful and thrilling book yet, a gorgeous evocation of the natural world and a powerful call to arms.
337 pages, Kindle Edition
First published August 1, 2023
807 people are currently reading
16225 people want to read
About the author
Susan Casey
9 books506 followersSusan Casey is the author of the “The Wave: In Pursuit of the Rogues, Freaks, and Giants of the Ocean,” and “The Devil’s Teeth: A True Story of Obsession and Survival Among America’s Great White Sharks.” Both books are New York Times bestsellers, with “The Wave” named one of 2010’s Most Notable Books. Her latest book, “Voices in the Ocean: A Journey Into the Wild and Haunting World of Dolphins,” was published by Knopf Doubleday in August 2015, and became a New York Times bestseller in its first week on sale. Voices was also chosen as one of Amazon’s Best Books of 2016.
“The Devil’s Teeth” was also a San Francisco Chronicle bestseller, a San Francisco Public Library Book Club Selection, a BookSense bestseller, a Barnes & Noble Discover Selection, a Library Journal Best Book of 2005, a 2005 NPR Summer Reading Selection, and a Hudson News Best Book of 2006. Outside magazine included it in “The New Adventure Library: The 32 Best of the 21st Century’s Books, Movies, and Videos.” Apple featured The Devil’s Teeth on its list of ten “iEssentials” in the Adventure and Travel category.
“The Wave” was also a Hudson News Best Book for 2010, an Indies Choice Award winner, and was featured on dozens of bestseller and critics’ best of the year lists. It won the North American Society for Oceanic History’s John Lyman Book Prize for Science and Technology, and an Indies’ Choice Award in 2011. Mens Journal named it one of “The 50 Greatest Adventure Books” of all time.
From 2009–2013, Casey served as the editor in chief of O, The Oprah Magazine. The publication is one of the country’s largest, with a monthly readership of 15 million women. In 2012, O won the National Magazine Award for General Excellence and the Clarion Award for Best Overall Magazine; during Casey’s tenure the title also garnered numerous other accolades and awards. Along with editing the magazine, Casey contributed to O as a writer, with features that included an odyssey into the world of spiritual healing, and a global scavenger hunt to discover nature’s most powerful superfoods.
In the course of reporting, Casey has lived among great white sharks, faced 70-foot waves off Maui’s north shore, ventured into the heart of the Gulf oil spill, trained as a sharpshooter, and performed as a mermaid in a giant tank, among other adventures. In 2008, she won a National Magazine Award for her Esquire feature, “75,” an investigation of what aging really means, as examined through the life of one exceptional man. In 2006, she received a National Magazine Award nomination for her story, “Our Oceans Are Turning to Plastic…Are You?” an environmental exposé on the dire impact plastic pollution in the oceans is having on planetary and human health. Her writing has appeared in Esquire, National Geographic, Fortune, Time, and Sports Illustrated, as well as the anthologies: “The Best American Science and Nature Writing,” “The Best American Sports Writing,” and “The Best American Magazine Writing.”
From 2000 to 2009, Casey was the development editor of Time Inc; the editor in chief of Sports Illustrated Women; and an editor at large for Time Inc.’s magazine titles. From 1994–1999, she was the creative director of Outside magazine, where she was part of the editorial team that published the original stories behind the bestselling books “Into Thin Air,” and “The Perfect Storm,” as well as the movie “Blue Crush.” During her tenure, Outside won three consecutive, history-making National Magazine Awards for General Excellence. Casey is the only person to have won this prize in all three disciplines: editing, writing, and art direction.
Casey has made frequent TV and radio appearances, including “The Oprah Winfrey Show,” “The Daily Show with Jon Stewart,” “Charlie Rose,” “Conan,” “Anderson Cooper 360,” “Nightline,” “Good Morning America,” “Today,” “The CBS Morning Show,” as well as many NPR outlets including Fresh Air, The Takeaway, and Life on Earth.
Casey lives in New York and
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Displaying 1 - 30 of 618 reviews
July 2, 2023
I must begin this review with a warning. Reading this book will turn you into an unstoppable well of horrifying/weird ocean facts. Depending on your friends--this may or may not kill at parties. I don’t go to parties, but my boyfriend suffered through three days of me reading whole paragraphs of this book out loud to him because I needed someone else to know the cool facts I was learning. This is a “I can’t shut up about this book” book. I can say it’s one of the best non-fiction books I’ve read so far this year, and it may end up topping that list when I make it in December.
You may think you know the ocean--cruising along the top in a boat or a kayak, sunning yourself on the shore, maybe scuba diving if you’re one of my more adventurous and outdoorsy friends. But this is the ocean as you have never seen it before. As with all immense natural forces that shape the ecology we live in, the ocean is larger, deeper, weirder, and more terrible than you have imagined.
Susan Casey is a masterful tour guide. At the beginning of the book, as she gushed about her love for the ocean, I thought that she maybe had a few screws loose. By the end I was trawling through the bibliography of the book to try to find more books about the ocean. Casey will make you fall in love, as you see the ocean through her own eyes.
Casey has smartly not ignored the people who have become enchanted by the deep. Her book is populated with characters whose bios seem made up. Like any insular scientific community, the scientists who specialize in the deep sea are larger than life, and, as Casey profiles them, impossible to forget.
If you love nature at its purest and most awesome, if you love grand stories of scientific discovery, if you love state of the art submarines, this book is a can't miss event for you. Thank you, Susan Casey, for allowing me to recapture the wonder and obsession of the ninth grader who read an article in National Geographic about what happens to whale carcasses when they fall to the sea floor, and proceeded to write her bio term paper on Whale Fall. I truly believe there’s something in this book for everyone
I received an advance copy of this book in exchange for this honest review.
You may think you know the ocean--cruising along the top in a boat or a kayak, sunning yourself on the shore, maybe scuba diving if you’re one of my more adventurous and outdoorsy friends. But this is the ocean as you have never seen it before. As with all immense natural forces that shape the ecology we live in, the ocean is larger, deeper, weirder, and more terrible than you have imagined.
Susan Casey is a masterful tour guide. At the beginning of the book, as she gushed about her love for the ocean, I thought that she maybe had a few screws loose. By the end I was trawling through the bibliography of the book to try to find more books about the ocean. Casey will make you fall in love, as you see the ocean through her own eyes.
Casey has smartly not ignored the people who have become enchanted by the deep. Her book is populated with characters whose bios seem made up. Like any insular scientific community, the scientists who specialize in the deep sea are larger than life, and, as Casey profiles them, impossible to forget.
If you love nature at its purest and most awesome, if you love grand stories of scientific discovery, if you love state of the art submarines, this book is a can't miss event for you. Thank you, Susan Casey, for allowing me to recapture the wonder and obsession of the ninth grader who read an article in National Geographic about what happens to whale carcasses when they fall to the sea floor, and proceeded to write her bio term paper on Whale Fall. I truly believe there’s something in this book for everyone
I received an advance copy of this book in exchange for this honest review.
September 14, 2023
Okay, the pun is irresistible: dive in, friends, dive in. The water's fine. Yes, it's deep -- some of the deepest parts of the ocean floor -- and Susan Casey brings it all to life. The flora, the fauna, the future, the beauty, the strangeness, and (Yes!) the danger. Casey is a terrific journalist and explorer, and her enthusiasm for the deep underworld of our watery planet is contagious. You'll be (NO pun, NO pun) hooked.
February 12, 2024
4✨
Literacy and reading is such a privilege, and it never feels so poignant until you pick up a book on any subject you could possibly imagine and explore. My student days may be done (longer ago than I want to accept, but that's another story), but as an avid reader, I'll be constantly learning for the rest of my life.
The Underworld: Journeys to the Depths of the Ocean by Susan Casey is an immaculately researched and well-developed nonfiction read about the fascinating wonders - and ominous unknowns - of the ocean and its deep, deep depths.
It's always a special touch when you have an author that truly lives and breathes their book subject, whether by in profession, education, research, exposure, etc. Casey's passion for the ocean is evident on every page, from her combination of personal accounts and second-hand stories, to the thematical composition of every chapter, and how it swells the story forward like a wave.
From an editorial standpoint, sometimes the paragraphs seemed to extend on for an awkwardly long amount of time, covering the full page (on my iPhone screen) before a break. There was also inconsistency with the use of quotes; they would be stacked together in paragraphs, versus starting new lines, so it sometimes made it a little hard to immediately attribute a quote to a specific person. However, aside from some sections feeling a little heavy, this didn't totally detract from my reading experience.
I loved seeing all the photos at the end; so great to put faces to names and sea creatures to visages!
Now, next time an ocean-related Jeopardy category comes on, I'm sooooo ready. Thanks Susan Casey!
Literacy and reading is such a privilege, and it never feels so poignant until you pick up a book on any subject you could possibly imagine and explore. My student days may be done (longer ago than I want to accept, but that's another story), but as an avid reader, I'll be constantly learning for the rest of my life.
The Underworld: Journeys to the Depths of the Ocean by Susan Casey is an immaculately researched and well-developed nonfiction read about the fascinating wonders - and ominous unknowns - of the ocean and its deep, deep depths.
It's always a special touch when you have an author that truly lives and breathes their book subject, whether by in profession, education, research, exposure, etc. Casey's passion for the ocean is evident on every page, from her combination of personal accounts and second-hand stories, to the thematical composition of every chapter, and how it swells the story forward like a wave.
From an editorial standpoint, sometimes the paragraphs seemed to extend on for an awkwardly long amount of time, covering the full page (on my iPhone screen) before a break. There was also inconsistency with the use of quotes; they would be stacked together in paragraphs, versus starting new lines, so it sometimes made it a little hard to immediately attribute a quote to a specific person. However, aside from some sections feeling a little heavy, this didn't totally detract from my reading experience.
I loved seeing all the photos at the end; so great to put faces to names and sea creatures to visages!
Now, next time an ocean-related Jeopardy category comes on, I'm sooooo ready. Thanks Susan Casey!
October 2, 2023
Ok … maybe it’s me. I’ve struggled finding books that I can enjoy enough to give a rating of over 3 stars. This one held hope as it had 4.34 collective stars on GR and was about a potentially fascinating topic. This is a very poor analogy, but I kind of felt like I was reading a book on the history of rock and roll that was written by a groupie. A groupie, defined as ‘a person … who regularly follows a pop music group or other celebrity in the hope of meeting or getting to know them.’
It had interesting moments, but not enough for me. Simply not enough science or information relative to the subject and way too much about the ‘celebrities’ the author met and got to know.
It had interesting moments, but not enough for me. Simply not enough science or information relative to the subject and way too much about the ‘celebrities’ the author met and got to know.
May 30, 2023
Prepare to be both horrified and mesmerized by the ocean in Susan Casey's, "The Underworld."
As a rule, I am not a fan of deep dark places which seem to have no end. My phobia was only reinforced by chapter 2 of this book which reads like a horror story. Casey chronicles the first deep sea dives and the reader can feel the claustrophobia along with at least 2 other phobias. I have never been more excited to be on land and not stuck in a cramp, cold, and damp sphere.
Nightmares aside, this book is excellent. Casey mixes the history of ocean exploration with her own modern day adventures. Casey is a great storyteller, but what truly makes this book special is her love of the ocean. It is palpable on every page and her excitement is infectious. I loved this book and even if you don't necessarily like the ocean or science, Casey will make you a convert.
Oh, and there are also ridiculous fish names. Did you know there is an assfish? Because there is an assfish.
(This book was provided as an advance copy by Netgalley and Doubleday Books.)
As a rule, I am not a fan of deep dark places which seem to have no end. My phobia was only reinforced by chapter 2 of this book which reads like a horror story. Casey chronicles the first deep sea dives and the reader can feel the claustrophobia along with at least 2 other phobias. I have never been more excited to be on land and not stuck in a cramp, cold, and damp sphere.
Nightmares aside, this book is excellent. Casey mixes the history of ocean exploration with her own modern day adventures. Casey is a great storyteller, but what truly makes this book special is her love of the ocean. It is palpable on every page and her excitement is infectious. I loved this book and even if you don't necessarily like the ocean or science, Casey will make you a convert.
Oh, and there are also ridiculous fish names. Did you know there is an assfish? Because there is an assfish.
(This book was provided as an advance copy by Netgalley and Doubleday Books.)
August 30, 2023
I did enjoy most of this book. However, the author made a number of errors of omission about easily searchable facts. Maybe I’m just being pedantic but I found them jarring and made me question the validity and reliability of the other facts she states.
In the prologue, she writes the sub is “one of a kind” while there are “3 Mars Rovers”. There have been 6 Mars Rovers, with 3 that are currently operational. But she doesn’t say “3 currently operating Mars Rovers”. It’s a minor detail made as a contrasting point but one that is inaccurate the way it is written in the text.
She tries to use space as a comparison for many things regarding exploration of the deep but seems unable to accurately make her point.
She states (somewhere around the 3rd or 4th chapter I think), that “Europa is Jupiter’s smallest moon”. Again, not correct. Yes it is the smallest of the four Galilean moons but it is no where near the smallest of Jupiter’s 95 moons. Written as is, it’s completely false.
I know it’s not a major thing and it wasn’t even directly relevant to the story she’s trying to tell. But these errors should have been caught in editing. They tweaked my brain and really had me questioning the rest of the data she was presenting.
In the prologue, she writes the sub is “one of a kind” while there are “3 Mars Rovers”. There have been 6 Mars Rovers, with 3 that are currently operational. But she doesn’t say “3 currently operating Mars Rovers”. It’s a minor detail made as a contrasting point but one that is inaccurate the way it is written in the text.
She tries to use space as a comparison for many things regarding exploration of the deep but seems unable to accurately make her point.
She states (somewhere around the 3rd or 4th chapter I think), that “Europa is Jupiter’s smallest moon”. Again, not correct. Yes it is the smallest of the four Galilean moons but it is no where near the smallest of Jupiter’s 95 moons. Written as is, it’s completely false.
I know it’s not a major thing and it wasn’t even directly relevant to the story she’s trying to tell. But these errors should have been caught in editing. They tweaked my brain and really had me questioning the rest of the data she was presenting.
October 10, 2025
4.5 stars. The author's complete, unbridled, unashamed passion for ocean exploration is absolutely infectious, and you can't help but become fascinated with what she's describing to you. The endlessly curious creatures that hide out of our reach will likely never be fully known, or even close to it, but it's definitely an area that I enjoy learning about.
July 4, 2025
This was a research book for me, but I really enjoyed this! Susan Casey is an excellent writer and I loved her information about the deep ocean. And I was surprised about just how much life lives in the deep.
April 24, 2025
My best nonfiction for 2025 so far. There is massive amounts of life at every depth in the ocean. It takes very adventurous people to explore this realm. Casey has the writing skills and research combined here to give us a very readable fact-filled book about the latest knowledge we have about the 98% of the Earth's biomass contained in our deep oceans.
**********
NY Times: 24 April 2025: Breaking News
TRUMP TAKES A MAJOR STEP TOWARD SEABED MINING IN INTERNATIONAL WATERS
https://www.nytimes.com/2025/04/24/cl...
NO ONE should be allowed to talk/vote on this issue unless they have fully read this book!!
Especially chapter 9: "Selling the Abyss"
Say goodbye to planet earth if this occurs :(
**********
All the deep-sea explorers are very smart people with tons of skills: scuba, mechanical, biology, archaeology, languages, fund-raising, business. It takes a tight team to pull off the balance of staying safe yet being aggressive to seek out these dangerous places to explore and collect data.
The ocean water column is made up of five zones:
1) the sunlight zone; 0-600 feet (200 m)
2) the twilight zone; 600-3,300 feet
3) the midnight zone; 3,300-10,000 feet
4) the abyssal zone; 10,000-20,000 feet
5) the hadal zone (trenches); 20,000-36,000 feet
The deepest known point in the ocean is Challenger Deep, located in the Mariana Trench, a region in the western Pacific Ocean. Challenger Deep has a depth of approximately 10,935 meters (35,876 feet) below sea level.
Marine archaeologists have the expertise. Governments have the rights. Commercial enterprises have the robots and the money but won't do anything for free. In a society that's figured out how to split the atom, couldn't there be a way to balance those interests?
This book travels all over the world, and is primarily focused on the bottom Hadal zone.
Why have we ignored so much of the deep for so long? It's as if we live in a mansion filled with treasures and artworks and fabulous animals, but haven't bothered to look in most of the rooms. It's a failure of curiosity, so say the least, a hobbling myopia that leaves us oddly unacquainted with our own home. For a species long on creativity and imagination, we've uncharacteristically limited ourselves in a range, our attention fixed outward and upward as if those were the only dimensions that countered.
This book is 90% adventure/science and 10% warnings.
Helping the science, OceanX is a nonprofit that has a mission to spread awe about the ocean.
They wanted to inspire people to care about it emotionally - because intellectual awareness of the ocean's majesty hasn't stopped us from polluting and plundering it."
All these new drones/robots are cool, but:
No kid ever dreamed of growing up to be a robot. But they do dream of being explorers.
There are some sad tales in here of finding TONS of unexploded and dangerous ordinance that was dumped off of wartime vessels. The microplastics and pollution found at even the deepest depths is extremely scary to read about.
Along with microplastics and synthetic fibers, in recent years scientists have found that the hadal trenches are thick with every toxin we've ever unleashed: persistent organic pollutants like PCBs (industrial poisons), PBDEs (flame retardants), DDT (pesticide), phthalates (Plasticizing chemicals), along with lead, mercury, pharmaceutical waste, and radioactive carbon from nuclear bombs.
When Sylvia Earle was asked if she had a favorite dive site, she replied:
Anywhere, fifty years ago.
This book doesn't need to get "preach" about this. The facts and data speak clearly. There are countries trying to buy pieces of deep-ocean bottom for mining. THANK GOODNESS they have gone bankrupt trying to deal with the insane size of a ship you'd need to to the 'harvesting' coupled with all the activist-law-suits.
The oceans cover the majority of our planet. Thankfully there are rich yacht-owners who are buying submersibles to cruise around in (and thus funding the submersible industry). These new underwater vehicles have leather seats and big bubble-windows.
While sunlight doesn't penetrate down past that first layer, there is still life thriving everywhere. This gives hope that we might find life under the surface of Jupiter's moon Europa, near hydrothermal vents, just the way we are finding these extremophiles here on Earth.
I wanted to read more, so I looked closely at the bibliography. There is not really a lot of great material out there to draw from. Much of the best knowledge is being gathered right now - today. See below for the list of 18 weblinks to institutions doing this research.
This all makes me want to go work for one of these organizations. Exploration with purpose (and impact)! Sign me up!
Solid 5* and onto my all-time-favorites.
Web for research and deep-sea institutes:
1. Caladan Oceanic: https://caladanoceanic.com/
2. Deep-Ocean Stewardship Initiative: https://www.dosi-project.org
3. Deep Sea Conservation Coalition: https://deep-sea-conservation.org/
4. EYOS Expeditions: https://www.eyos-expeditions.com/
5. Five Deeps Expedition: https://fivedeeps.com/
6. Inkfish: https://ink.fish/ or https://www.instagram.com/inkfishexpe...
7. Marine Technology Society: https://www.mtsociety.org/
8. Minderoo - UWA Deep Sea Research Center: https://www.uwa.edu.au/oceans-institu...
9. Mission Blue: https://missionblue.org/
10. Monterey Bay Aquarium Research Institute: https://www.mbari.org/
11. Nautilus Live Ocean Expedition Trust: https://nautiluslive.org/
12. OceanX: https://oceanx.org/
13. NOAA Ocean Explorer: https://www.oceanexplorer.noaa.gov/
14. Schmidt Ocean Institute: https://schmidtocean.org/
15. Scripps Institution of Oceanography: https://scripps.ucsd.edu/
16. Triton Submarines: https://tritonsubs.com/
17. U of Washington School of Oceanography: https://www.ocean.washington.edu/
18. Woods Hole Oceanographic Institution: https://www.whoi.edu/
**********
NY Times: 24 April 2025: Breaking News
TRUMP TAKES A MAJOR STEP TOWARD SEABED MINING IN INTERNATIONAL WATERS
https://www.nytimes.com/2025/04/24/cl...
NO ONE should be allowed to talk/vote on this issue unless they have fully read this book!!
Especially chapter 9: "Selling the Abyss"
Say goodbye to planet earth if this occurs :(
**********
All the deep-sea explorers are very smart people with tons of skills: scuba, mechanical, biology, archaeology, languages, fund-raising, business. It takes a tight team to pull off the balance of staying safe yet being aggressive to seek out these dangerous places to explore and collect data.
The ocean water column is made up of five zones:
1) the sunlight zone; 0-600 feet (200 m)
2) the twilight zone; 600-3,300 feet
3) the midnight zone; 3,300-10,000 feet
4) the abyssal zone; 10,000-20,000 feet
5) the hadal zone (trenches); 20,000-36,000 feet
The deepest known point in the ocean is Challenger Deep, located in the Mariana Trench, a region in the western Pacific Ocean. Challenger Deep has a depth of approximately 10,935 meters (35,876 feet) below sea level.
Marine archaeologists have the expertise. Governments have the rights. Commercial enterprises have the robots and the money but won't do anything for free. In a society that's figured out how to split the atom, couldn't there be a way to balance those interests?
This book travels all over the world, and is primarily focused on the bottom Hadal zone.
Why have we ignored so much of the deep for so long? It's as if we live in a mansion filled with treasures and artworks and fabulous animals, but haven't bothered to look in most of the rooms. It's a failure of curiosity, so say the least, a hobbling myopia that leaves us oddly unacquainted with our own home. For a species long on creativity and imagination, we've uncharacteristically limited ourselves in a range, our attention fixed outward and upward as if those were the only dimensions that countered.
This book is 90% adventure/science and 10% warnings.
Helping the science, OceanX is a nonprofit that has a mission to spread awe about the ocean.
They wanted to inspire people to care about it emotionally - because intellectual awareness of the ocean's majesty hasn't stopped us from polluting and plundering it."
All these new drones/robots are cool, but:
No kid ever dreamed of growing up to be a robot. But they do dream of being explorers.
There are some sad tales in here of finding TONS of unexploded and dangerous ordinance that was dumped off of wartime vessels. The microplastics and pollution found at even the deepest depths is extremely scary to read about.
Along with microplastics and synthetic fibers, in recent years scientists have found that the hadal trenches are thick with every toxin we've ever unleashed: persistent organic pollutants like PCBs (industrial poisons), PBDEs (flame retardants), DDT (pesticide), phthalates (Plasticizing chemicals), along with lead, mercury, pharmaceutical waste, and radioactive carbon from nuclear bombs.
When Sylvia Earle was asked if she had a favorite dive site, she replied:
Anywhere, fifty years ago.
This book doesn't need to get "preach" about this. The facts and data speak clearly. There are countries trying to buy pieces of deep-ocean bottom for mining. THANK GOODNESS they have gone bankrupt trying to deal with the insane size of a ship you'd need to to the 'harvesting' coupled with all the activist-law-suits.
The oceans cover the majority of our planet. Thankfully there are rich yacht-owners who are buying submersibles to cruise around in (and thus funding the submersible industry). These new underwater vehicles have leather seats and big bubble-windows.
While sunlight doesn't penetrate down past that first layer, there is still life thriving everywhere. This gives hope that we might find life under the surface of Jupiter's moon Europa, near hydrothermal vents, just the way we are finding these extremophiles here on Earth.
I wanted to read more, so I looked closely at the bibliography. There is not really a lot of great material out there to draw from. Much of the best knowledge is being gathered right now - today. See below for the list of 18 weblinks to institutions doing this research.
This all makes me want to go work for one of these organizations. Exploration with purpose (and impact)! Sign me up!
Solid 5* and onto my all-time-favorites.
Web for research and deep-sea institutes:
1. Caladan Oceanic: https://caladanoceanic.com/
2. Deep-Ocean Stewardship Initiative: https://www.dosi-project.org
3. Deep Sea Conservation Coalition: https://deep-sea-conservation.org/
4. EYOS Expeditions: https://www.eyos-expeditions.com/
5. Five Deeps Expedition: https://fivedeeps.com/
6. Inkfish: https://ink.fish/ or https://www.instagram.com/inkfishexpe...
7. Marine Technology Society: https://www.mtsociety.org/
8. Minderoo - UWA Deep Sea Research Center: https://www.uwa.edu.au/oceans-institu...
9. Mission Blue: https://missionblue.org/
10. Monterey Bay Aquarium Research Institute: https://www.mbari.org/
11. Nautilus Live Ocean Expedition Trust: https://nautiluslive.org/
12. OceanX: https://oceanx.org/
13. NOAA Ocean Explorer: https://www.oceanexplorer.noaa.gov/
14. Schmidt Ocean Institute: https://schmidtocean.org/
15. Scripps Institution of Oceanography: https://scripps.ucsd.edu/
16. Triton Submarines: https://tritonsubs.com/
17. U of Washington School of Oceanography: https://www.ocean.washington.edu/
18. Woods Hole Oceanographic Institution: https://www.whoi.edu/
January 13, 2024
This was such an engaging, educational and page turning read! I really enjoyed learning more about the intricacies of deep sea submersible diving, as well as the importance of deep sea exploration in a world increasingly affected by climate change. I would highly recommend this to anyone interested in the deep ocean.
January 9, 2024
In The Underworld: Journeys to the Depths of the Ocean, science journalist Susan Cacey writes about deep ocean exploration. It’s roughly organized in chronicle order, from the imaginary deep sea creatures dreamed up by Olaus Magnus, a 16th century Swedish monk, to the first deep-sea dive by William Beebe and Otis Barton in the first ever bathyscaphe in 1930s using, to Don Walsh and Jacques Piccard’s dive to Marianas Trench in 1960s, and to modern day deep sea divings.
Susan Casey is passionate about the ocean. She points out the US government spends much less in ocean research than in space exploration. It is often said we know more about outer space than the ocean in our backyard. She considers the reason: “Why have we ignored so much of the deep for so long? It’s as if we live in a mansion filled with treasures and artworks and fabulous animals, but haven’t bothered to look in most of the rooms. It’s a failure of curiosity, to say the least, a hobbling myopia that leaves us oddly unacquainted with our own home. For a species long on creativity and imagination, we’ve uncharacteristically limited ourselves in range, our attentions fixed outward and upward as if those were the only dimensions that counted. Maybe that’s because seven miles down, we aren't in a position to call the shots. In the deep, humanity can’t even pretend to be in charge. Of course we are not in charge of space, either, but exploring upward gives us the illusion of expansion, as though we’re conquering territory, extending our ever-acquisitive reche. In this mindset, to go inward, into the abyss, is to be stuck with what we already have.”
Can I have both space and ocean exploration?
It is fascinating to read the various submersibles and diving adventures. Two vehicles, Alvin, the US Navy’s deep-sea research submersible, and Limiting Factor, the submersible made by Triton Submarines to Victor Vescovo, stood out. The author praises Victor Vescovo and Ray Dalio, two investors, especially the former, for providing scientists the much needed rides to the deep.
It’s very hard to read the chapter about deep-sea net fishing (hey, Norway!) and deep-sea mining. What I like most is the description of deep sea creatures. Overall, the deep sea is the opposite of a desert. It is a rich ecosystem or ecosystems with many creatures unknown to us.
Quotes:
P137:
Hadal snailfish have no swim bladders or air cavities in their bodies; their innards are encased in a buoyang, transparent gel. Their bones are demineralized, giving them a floppy skeleton, and they lack a fully closed skull. “They need the pressure to maintain their body form,” Jamieson said. “When you pick them up they’re very, very delicate. It’s like handling a water-filled condom. They slip around in your hand.”
……
The more I learned about snailfish, the more they charmed me. Of all the contenders for top predator in the harshest environment on earth–and the winner was a pink gummy bear? “They’re great because they’re the deepest fish in the world and they’re not even a deep-sea fish,” Jamieson explained. “They’re a shallow-water fish that’s so audacious it’s overtaken all the deep-sea fish.” Even now, hundreds of snailfish species live closer to the surface. But twenty million years ago, some of them began to venture downward. They moved from sunning themselves in tide pools and estuaries to hunting amphipods in hadal trenches at evolutionary warp speed.
P210-211:
To my left, a siphonophore glowed like a nebula; a jellyfish stoned and revealed itself to be shaped like a dahlia.
……
In the deep, light is a strategy, a tool, a weapon. It’s a language–the most common form of communication on earth. Even the bacteria are fluent.
……
Bioluminescence is handy for both offense and defense. The Colobonema jellyfish, for instance, has thirty-two tentacles attached to a transparent bell. When threatened, it ignites the lights on its tentacles, waves them like sparklers, and then ejects them, distracting the attacker with a mass of shimmering spaghetti while the bell makes a surreptitious getaway. (Later, the tentacles grow back.) The stoplight loosejaw dragonfish flicks on crafty red photophores beneath its eyes. Most deep-sea creatures are highly attuned to blue light and can’t see red light at all, so the stoplight loosejaw is effectively staking them with night-vision goggles. Squid have been known to hunt with their lights off, and then strike in a blaze of brightness that stuns their prey. Some creatures squirt gobs of light, tagging their enemies. Many creatures camouflage themselves by dialing their photophores up and down like a dimmer switch to erase their silhouettes. Those are merely a few examples. Twilight zone creatures have as many different ways to wield light as there are facets on a disco ball.
P212:
We continued our free fall, like swirling around us. Two thousand feet was a catwalk of jellyfish, each one showier than the next. They sashayed by under frilly umbrellas, trailing diaphanous wisps amd ,pde;;omg the latest in fashionable lights. Jellies are often referred to as ‘simple’ creatures because they lack brains, blood, bones, and a heart. Watching them, I found that description laughable. They’re the most efficient swimmers in the animal kingdom. They’re also willy hunters that can eat just about anything, including fish, crustaceans, and each other. The box jellyfish has twenty-four eyes–including some with lenses, corneas, and retinas–and packs the planet’s most venomous stings. Another jellyfish species is biologically immortal: it can reverse its life cycle and rebirth itself. To me, those seem like pretty advanced tricks.
P218:
Earth’s biosphere is 95 percent deep ocean, and that ocean is four billion years old. If you think too hard about numbers like that, terror can trickle in. But there’s grace in blowing down to the deep’s sublime dimensions: a peacefulness that comes from knowing your place in the true order of things.
59% (I switched to kindle version):
An estimated 90 percent of the animals collected have been new species: corals like pearl necklaces and anemones like dripping flowers and pearl-white brittle stars and acid-yellow sea cucumbers with huge swishy tails; urchins that gallop across the bottom and glass sponges that house so many residents they’re like apartment buildings designed by Dr. Seuss.
Susan Casey is passionate about the ocean. She points out the US government spends much less in ocean research than in space exploration. It is often said we know more about outer space than the ocean in our backyard. She considers the reason: “Why have we ignored so much of the deep for so long? It’s as if we live in a mansion filled with treasures and artworks and fabulous animals, but haven’t bothered to look in most of the rooms. It’s a failure of curiosity, to say the least, a hobbling myopia that leaves us oddly unacquainted with our own home. For a species long on creativity and imagination, we’ve uncharacteristically limited ourselves in range, our attentions fixed outward and upward as if those were the only dimensions that counted. Maybe that’s because seven miles down, we aren't in a position to call the shots. In the deep, humanity can’t even pretend to be in charge. Of course we are not in charge of space, either, but exploring upward gives us the illusion of expansion, as though we’re conquering territory, extending our ever-acquisitive reche. In this mindset, to go inward, into the abyss, is to be stuck with what we already have.”
Can I have both space and ocean exploration?
It is fascinating to read the various submersibles and diving adventures. Two vehicles, Alvin, the US Navy’s deep-sea research submersible, and Limiting Factor, the submersible made by Triton Submarines to Victor Vescovo, stood out. The author praises Victor Vescovo and Ray Dalio, two investors, especially the former, for providing scientists the much needed rides to the deep.
It’s very hard to read the chapter about deep-sea net fishing (hey, Norway!) and deep-sea mining. What I like most is the description of deep sea creatures. Overall, the deep sea is the opposite of a desert. It is a rich ecosystem or ecosystems with many creatures unknown to us.
Quotes:
P137:
Hadal snailfish have no swim bladders or air cavities in their bodies; their innards are encased in a buoyang, transparent gel. Their bones are demineralized, giving them a floppy skeleton, and they lack a fully closed skull. “They need the pressure to maintain their body form,” Jamieson said. “When you pick them up they’re very, very delicate. It’s like handling a water-filled condom. They slip around in your hand.”
……
The more I learned about snailfish, the more they charmed me. Of all the contenders for top predator in the harshest environment on earth–and the winner was a pink gummy bear? “They’re great because they’re the deepest fish in the world and they’re not even a deep-sea fish,” Jamieson explained. “They’re a shallow-water fish that’s so audacious it’s overtaken all the deep-sea fish.” Even now, hundreds of snailfish species live closer to the surface. But twenty million years ago, some of them began to venture downward. They moved from sunning themselves in tide pools and estuaries to hunting amphipods in hadal trenches at evolutionary warp speed.
P210-211:
To my left, a siphonophore glowed like a nebula; a jellyfish stoned and revealed itself to be shaped like a dahlia.
……
In the deep, light is a strategy, a tool, a weapon. It’s a language–the most common form of communication on earth. Even the bacteria are fluent.
……
Bioluminescence is handy for both offense and defense. The Colobonema jellyfish, for instance, has thirty-two tentacles attached to a transparent bell. When threatened, it ignites the lights on its tentacles, waves them like sparklers, and then ejects them, distracting the attacker with a mass of shimmering spaghetti while the bell makes a surreptitious getaway. (Later, the tentacles grow back.) The stoplight loosejaw dragonfish flicks on crafty red photophores beneath its eyes. Most deep-sea creatures are highly attuned to blue light and can’t see red light at all, so the stoplight loosejaw is effectively staking them with night-vision goggles. Squid have been known to hunt with their lights off, and then strike in a blaze of brightness that stuns their prey. Some creatures squirt gobs of light, tagging their enemies. Many creatures camouflage themselves by dialing their photophores up and down like a dimmer switch to erase their silhouettes. Those are merely a few examples. Twilight zone creatures have as many different ways to wield light as there are facets on a disco ball.
P212:
We continued our free fall, like swirling around us. Two thousand feet was a catwalk of jellyfish, each one showier than the next. They sashayed by under frilly umbrellas, trailing diaphanous wisps amd ,pde;;omg the latest in fashionable lights. Jellies are often referred to as ‘simple’ creatures because they lack brains, blood, bones, and a heart. Watching them, I found that description laughable. They’re the most efficient swimmers in the animal kingdom. They’re also willy hunters that can eat just about anything, including fish, crustaceans, and each other. The box jellyfish has twenty-four eyes–including some with lenses, corneas, and retinas–and packs the planet’s most venomous stings. Another jellyfish species is biologically immortal: it can reverse its life cycle and rebirth itself. To me, those seem like pretty advanced tricks.
P218:
Earth’s biosphere is 95 percent deep ocean, and that ocean is four billion years old. If you think too hard about numbers like that, terror can trickle in. But there’s grace in blowing down to the deep’s sublime dimensions: a peacefulness that comes from knowing your place in the true order of things.
59% (I switched to kindle version):
An estimated 90 percent of the animals collected have been new species: corals like pearl necklaces and anemones like dripping flowers and pearl-white brittle stars and acid-yellow sea cucumbers with huge swishy tails; urchins that gallop across the bottom and glass sponges that house so many residents they’re like apartment buildings designed by Dr. Seuss.
September 29, 2024
Susan Casey first came to my attention when a man in our book club suggested we read The Wave. Who knew a book about surfing, a sport I know nothing about, could be so compelling?
I thought The Wave was very good, and The Underworld is even better. Somehow I had the idea that the ocean depths were... well, empty. Wrong. Not only are the ocean depths not empty, but they contain forms of life that are novel and unique to the depths.
Scientists do not know much about the depths---it is very difficult for humans to visit the deepest parts of the oceans---and Casey urges us to put off proposed mining ventures until more can be known about these parts of the world.
I loved reading about the explorers of the ocean floor. I think I might be a Susan Casey fan.
I thought The Wave was very good, and The Underworld is even better. Somehow I had the idea that the ocean depths were... well, empty. Wrong. Not only are the ocean depths not empty, but they contain forms of life that are novel and unique to the depths.
Scientists do not know much about the depths---it is very difficult for humans to visit the deepest parts of the oceans---and Casey urges us to put off proposed mining ventures until more can be known about these parts of the world.
I loved reading about the explorers of the ocean floor. I think I might be a Susan Casey fan.
September 20, 2024
Rating: 3.5 stars
The subtitle "Journeys to the Depth of the Ocean" is essentially what this book is about. This isn't so much a natural science book about the critters in the ocean depths, but focuses on the history of manned and unmanned (robots) submersibles, the people who forked out boat-loads of cash to have them designed and built, and the experiences of the people who dive in them.
Manned submersibles carry passengers, who sit within dry, pressure-controlled cabin equipped with life-support systems and a breathable atmosphere. These submersible require a support vessel and crew to transport, launch, and recover the submersible. But once underwater these submersibles can move independently and explore the ocean depths. These submersibles are battery operated so can only stay underwater for approximately half a day or so. Globe-trotting Susan Casey meets up with various scientists, submersible pilots and explorers as they dive to the ocean depth for research to determine what's down there (fascinating creatures and splendid geological formations), for marine archeology purposes and the retrieval/study of lost shipwrecks (including naval vessels, Spanish treasure Galleons, and the Titanic), and also just for the sheer thrill of it. The author interviews pilots and passengers to gain a semblance of their experience, and also goes on a dive herself. These undersea stories are fascinating, and at times, nail biting. The chapter on deep sea mining is truly a horror story. Unfortunately it's real and it seems that it's up to the general population to stop it.
I would have loved more information about the actual deep ocean - the animals and geological process, but as it is, this book is interesting and makes a lovely companion to The Bathysphere Book by Brad Fox; The Brilliant Abyss by Helen Scales; and Below the Edge of Darkness by Edith Widder.
ADDENDUM 1: https://www.vanityfair.com/news/2023/...
ADDENDUM 2: https://fivedeeps.com/
The subtitle "Journeys to the Depth of the Ocean" is essentially what this book is about. This isn't so much a natural science book about the critters in the ocean depths, but focuses on the history of manned and unmanned (robots) submersibles, the people who forked out boat-loads of cash to have them designed and built, and the experiences of the people who dive in them.
Manned submersibles carry passengers, who sit within dry, pressure-controlled cabin equipped with life-support systems and a breathable atmosphere. These submersible require a support vessel and crew to transport, launch, and recover the submersible. But once underwater these submersibles can move independently and explore the ocean depths. These submersibles are battery operated so can only stay underwater for approximately half a day or so. Globe-trotting Susan Casey meets up with various scientists, submersible pilots and explorers as they dive to the ocean depth for research to determine what's down there (fascinating creatures and splendid geological formations), for marine archeology purposes and the retrieval/study of lost shipwrecks (including naval vessels, Spanish treasure Galleons, and the Titanic), and also just for the sheer thrill of it. The author interviews pilots and passengers to gain a semblance of their experience, and also goes on a dive herself. These undersea stories are fascinating, and at times, nail biting. The chapter on deep sea mining is truly a horror story. Unfortunately it's real and it seems that it's up to the general population to stop it.
I would have loved more information about the actual deep ocean - the animals and geological process, but as it is, this book is interesting and makes a lovely companion to The Bathysphere Book by Brad Fox; The Brilliant Abyss by Helen Scales; and Below the Edge of Darkness by Edith Widder.
ADDENDUM 1: https://www.vanityfair.com/news/2023/...
ADDENDUM 2: https://fivedeeps.com/
January 16, 2024
I enjoyed Casey's enthusiasm and all the historical and technical details covered in the book, but I am growing a little concerned that the conclusion various authors of books about ocean exploration seem to reach is that we should endeavour to, and please read this with whimsy and childlike wonder in your heart, get everyone to experience the mysteries of the depths, and that way, perhaps, we'd understand ocean mining is a bad idea.
Listen, I do not need to get into a submarine to experience the wonders of the depths, as much as I would like to, and neither do most people. It seems to me that encouraging ecotourism is the worst possible approach to ocean conservation. I am entirely on board (pun not intended) with scientists gathering data, but the rest of us should really stick to the recordings they upload to YouTube. And also not mine the ocean. We seem to have learned nothing at all.
Listen, I do not need to get into a submarine to experience the wonders of the depths, as much as I would like to, and neither do most people. It seems to me that encouraging ecotourism is the worst possible approach to ocean conservation. I am entirely on board (pun not intended) with scientists gathering data, but the rest of us should really stick to the recordings they upload to YouTube. And also not mine the ocean. We seem to have learned nothing at all.
October 4, 2024
BTP nonfiction finalist
Read
August 27, 2023it's very white, which is unavoidable due to the prohibitive cost of deep-sea exploration and the extremely cishet white male makeup of the submersible industry. however, i wish she had interrogated that whiteness and richness a lot more. there are mentions of the effects of colonialism, of ancient indigenous knowledge of things white people "discovered" only recently, of groups that are fighting to counteract climate change, of a lot of other things that could have been developed into a clear portrait of exactly who has been fucking up the ocean all these years and who has been steadily working to counteract these damages, but it doesn't go beneath the surface of that, and that's my one critique.
aside from that, holy shit. i loved this. could not put it down, set aside all my other books, binged it, stayed up past bedtime, etc etc. highly recommend if you wanna cry about the ocean. also, "the ocean as metaphor for queerness" factor is just....................,,,, off the charts in this book
aside from that, holy shit. i loved this. could not put it down, set aside all my other books, binged it, stayed up past bedtime, etc etc. highly recommend if you wanna cry about the ocean. also, "the ocean as metaphor for queerness" factor is just....................,,,, off the charts in this book
March 8, 2025
Casey brings the depths of the oceans to life here. She offers a glimpse into the many layers of the ocean. There is so much we don't know about all that life below us. It takes a real adventurer to delve so far below the ocean. I'm not sure I could do it myself, so I'm glad to learn through the intrepidness of others.
Casey does a great job of discussing the importance of mapping the ocean floor and of exploring all of the life that teems below. She highlights the many men and women that have devoted their lives and money to something often overlooked by the larger science community. The money needed to fund the many underwater vessels is typically from the private sector.
There are many pictures included (which I loved).
Casey does a great job of discussing the importance of mapping the ocean floor and of exploring all of the life that teems below. She highlights the many men and women that have devoted their lives and money to something often overlooked by the larger science community. The money needed to fund the many underwater vessels is typically from the private sector.
There are many pictures included (which I loved).
November 14, 2023
There isn't a clear audience for this book. A magazine journalist wrote a book about the deep sea. She has written previous best sellers so it somehow warranted her access and privilege in the deep sea exploration community and to get in on a coveted dive when others have dedicated and invested their lives and careers into the field. It's like the celebrity first pitch of a game, in book form. This topic is incredible in itself. The individuals that get named dropped are legends and definitely read more about them and check out all the documentaries mentioned but this book is a humble brag Instagram post at best.
It's more a woman's personal experience tagging along with experts in the field and then getting handed the controls in a one in a lifetime dive to drive a submersible without any training or experience. It's a brief history of ocean exploration, repetitive if you know anything about the field and then pictures and anecdotes about her trip like a travel magazine article. In fact in her acknowledgements she says she wrote of the Five Deeps previously . . . for Outside magazine. She doesn't have a biology, oceanography, marine sciences or engineering degree to reference or elaborate on the material. As other comments state, it doesn't have an index to be a scientific non-fiction. It's more like a researched journal of a privileged person's vacation. Who is this book intended for?!?!
It's already irrelevant. Not only have other comments mentioned statements she made to be factual wrong and scientifically inaccurate and easily fact checked, but now this book is cavalier to the incident of June 2023. She jokes about driving the submersible backwards and being allowed to pilot it. This book is already now outdated since it states "No one has died in a manned submersible since 1974." Don't waste your time with this one.
The Deepest Map by Laura Trethewey came out right before this and is waaaaayyy better with much of the same information and even the same dives, people and interviews.
It's more a woman's personal experience tagging along with experts in the field and then getting handed the controls in a one in a lifetime dive to drive a submersible without any training or experience. It's a brief history of ocean exploration, repetitive if you know anything about the field and then pictures and anecdotes about her trip like a travel magazine article. In fact in her acknowledgements she says she wrote of the Five Deeps previously . . . for Outside magazine. She doesn't have a biology, oceanography, marine sciences or engineering degree to reference or elaborate on the material. As other comments state, it doesn't have an index to be a scientific non-fiction. It's more like a researched journal of a privileged person's vacation. Who is this book intended for?!?!
It's already irrelevant. Not only have other comments mentioned statements she made to be factual wrong and scientifically inaccurate and easily fact checked, but now this book is cavalier to the incident of June 2023. She jokes about driving the submersible backwards and being allowed to pilot it. This book is already now outdated since it states "No one has died in a manned submersible since 1974." Don't waste your time with this one.
The Deepest Map by Laura Trethewey came out right before this and is waaaaayyy better with much of the same information and even the same dives, people and interviews.
August 15, 2023
in the abyss, you don't glimpse the mystery—you enter it, and your consciousness is the only fixed point. subtract time and you're left with presence. in the deep, you lose your bearings and you find yourself.it can be very tough to get through one of susan casey's books, as every page invariably leads to myriad google queries, wikipedia look-ups, and never-ending image searches. casey's latest, the underworld, is an altogether riveting exploration of the deep sea. traversing the globe across ten chapters, casey blends pop science, first-person reporting, and a contagious oceanic enthusiasm into an irresistibly fascinating look at our planet's underwater depths. from a cornucopia of otherworldly marine creatures, submersible trips into the hadal zone, and ever-present deep sea mining threats, the underworld is an engrossing journey into our planet's subaqueous secrets.
January 7, 2024
A deep sea travelogue by a journalist who's immersed herself (pun intended) in the field. Casey discusses the history of underwater exploration and provides a compelling case for the preservation of these delicate, difficultly-traversed ecosystems. Research for her book led her to spend years traveling and joining in many underwater expeditions herself, despite ostensibly not being a scientist or researcher herself. She talks about how submersible vehicles have a stellar safety record, so I presume this book went to press before the Titan submersible implosion in June 2023. This book is somewhat interesting, though I would have appreciated a larger focus on the science of deep sea vents and deep sea creatures, rather than a tourist/layperson perspective.
April 7, 2025
It wasn't what I expected... I don't tend to read the book descriptions very carefully because I hate the spoilers that tend to riddle those. I should probably revise that policy when it comes to non-fiction popular science books, but alas, the habit stuck. I was expecting a book on the denizens of the ocean floor: an exploration into their lives and interactions with each other (or maybe even humans). This was not that.
Instead, it was about the history of deep ocean exploration and also the author's own forays into its depth. I still enjoyed it and found it quite interesting, but I was still disappointed that it didn't have more about the actual animals down there and what we learned from them.
Key takeaways:
-The deep ocean is filled with a lot more life than most people believe. Furthermore, they are tinier while also being a lot more important than most people believe. They are the foundation on which life on Earth was built and on which it still relies today.
-Deep ocean mining threatens this ecosystem with regulatory bodies woefully failing at their job of protecting it (is anyone surprised at this?).
-Mining companies want to greenwash deep sea mining by claiming we need the metals down there for our electric vehicles and that it will do nothing but stir up some dust. The reality being that what they want to do is basically vacuum up everything indiscriminately, grab what they want, shred everything else (live beings included), and then dump the waste back into the ocean, creating a massive storm of dust that would choke out any remaining life. Think Mount Vesuvius and Pompeii.
-Gabe Newell of Valve (Steam) fame now owns the sub that a lot of this book is about: The Limiting Factor. He plans to keep exploring the depth. I had no idea Gabe did stuff like this, but it was a cool thing to find out at the end.
Instead, it was about the history of deep ocean exploration and also the author's own forays into its depth. I still enjoyed it and found it quite interesting, but I was still disappointed that it didn't have more about the actual animals down there and what we learned from them.
Key takeaways:
-The deep ocean is filled with a lot more life than most people believe. Furthermore, they are tinier while also being a lot more important than most people believe. They are the foundation on which life on Earth was built and on which it still relies today.
-Deep ocean mining threatens this ecosystem with regulatory bodies woefully failing at their job of protecting it (is anyone surprised at this?).
-Mining companies want to greenwash deep sea mining by claiming we need the metals down there for our electric vehicles and that it will do nothing but stir up some dust. The reality being that what they want to do is basically vacuum up everything indiscriminately, grab what they want, shred everything else (live beings included), and then dump the waste back into the ocean, creating a massive storm of dust that would choke out any remaining life. Think Mount Vesuvius and Pompeii.
-Gabe Newell of Valve (Steam) fame now owns the sub that a lot of this book is about: The Limiting Factor. He plans to keep exploring the depth. I had no idea Gabe did stuff like this, but it was a cool thing to find out at the end.
September 22, 2023
I really wish this contained an index…
The Underworld: Journeys to the Depths of the Ocean by Susan Casey is essentially a collection of personal underwater travel essays mixed in with a history of sea exploration…
It’s hard to describe this book as j became aware of it because of the writer’s expertise in the underwater world.
She goes over a significant amount of her journeys in the last frontier of earth (and I REALLY liked the map on the inside cover), while covering different generations of ocean travel, with shoutouts to some of the aquatic pioneers of the past…
I would have liked it if there was more order to the book. This isn’t a travel guide of a novel about sunken treasure. This is meant to be a quasi historical retrospective on the deep blue sea and mankind’s relationship with it…I think…unless it is meant to just be a travel journal with historical anecdotes mixed in…
This booo felt like it was trying to be two different things when it should have been just one thing…
I did like all the detail it went into even if it didn’t always make sense to go off on historical tangents at the time…
Also it really should have had an index…
The Underworld: Journeys to the Depths of the Ocean by Susan Casey is essentially a collection of personal underwater travel essays mixed in with a history of sea exploration…
It’s hard to describe this book as j became aware of it because of the writer’s expertise in the underwater world.
She goes over a significant amount of her journeys in the last frontier of earth (and I REALLY liked the map on the inside cover), while covering different generations of ocean travel, with shoutouts to some of the aquatic pioneers of the past…
I would have liked it if there was more order to the book. This isn’t a travel guide of a novel about sunken treasure. This is meant to be a quasi historical retrospective on the deep blue sea and mankind’s relationship with it…I think…unless it is meant to just be a travel journal with historical anecdotes mixed in…
This booo felt like it was trying to be two different things when it should have been just one thing…
I did like all the detail it went into even if it didn’t always make sense to go off on historical tangents at the time…
Also it really should have had an index…
December 25, 2023
What i wanted from the book: learn about the science of the deep sea and its inhabitants
What i got from the book: Susan’s deep sea travel experiences and conversations with the experts. Which is exactly what the book’s summary says, so if you are after this you’ll enjoy this book. Was disappointed because I read the GR reviews beforehand and thought there would be more science to it.
What i got from the book: Susan’s deep sea travel experiences and conversations with the experts. Which is exactly what the book’s summary says, so if you are after this you’ll enjoy this book. Was disappointed because I read the GR reviews beforehand and thought there would be more science to it.
January 15, 2025
10 stars! Seriously, every person living on this planet should have to read this book!
Amazing what we do not know and how can we not care to know or to protect what is obviously the basis of life and the core of the ecosystem of this planet?!?
And, of course, the greedy humans are plotting and planning to destroy it all. Mining. Yeah. Deep. Sea. Mining. Not enough that we're killing the topmost portion of the planet where we actually live, but we have already unbelievably polluted the "underworld' as well. STOP! Just stop and think! Honestly, the human race deserves annihilation. We have created and perpetrated our own destruction. So stop!!
Casey's writing style is enthralling, IMO! Loved this! So much to learn!!
Amazing what we do not know and how can we not care to know or to protect what is obviously the basis of life and the core of the ecosystem of this planet?!?
And, of course, the greedy humans are plotting and planning to destroy it all. Mining. Yeah. Deep. Sea. Mining. Not enough that we're killing the topmost portion of the planet where we actually live, but we have already unbelievably polluted the "underworld' as well. STOP! Just stop and think! Honestly, the human race deserves annihilation. We have created and perpetrated our own destruction. So stop!!
Casey's writing style is enthralling, IMO! Loved this! So much to learn!!
June 8, 2024
My nonfiction shelf is packed with Susan Casey books. She’s taught me everything I know about shark secrets and rogue waves, so I was thrilled to dive into the deepest fathoms of the abyss in her latest release. This is the perfect book to read as you lie on a warm beach with cool waves lapping at your feet… if you can handle knowing how deep and dark that water truly gets.
October 18, 2023
Parts of this book were interesting and even fascinating, others were not of interest to me. If I wasn’t listening to this, I probably wouldn’t have finished it cuz it’s so dense. I’ve always been interested in the ocean so it did give me a greater knowledge and appreciation for it.
October 19, 2023
If I could give this book 6 stars I would. Could not put it down and there are great photos from the abyss. If you've ever wondered what's down there at 35000 feet read this and you'll know. And why we should all care.
August 29, 2023
Definitely piqued my interest about the depths of our oceans.
The book is a collection of many underwater happenings, some of them unrelated to each other, spread across archaeological, scientific, exploratory, adventurous and destructive topics, bound together by Susan's fascination with the deep.
The book is a collection of many underwater happenings, some of them unrelated to each other, spread across archaeological, scientific, exploratory, adventurous and destructive topics, bound together by Susan's fascination with the deep.
January 23, 2026
A bit behind on my reviewing, but I'll catch up when I'm out of this life slump..
The Underworld was one of my favourite 2025 reads. I've read other books by this author and enjoyed all of of them, happy that this was another winner. This is an amazing read, this time about deep sea exploration and submersibles. A good combination of stories, historical research and personal adventures made the pages go by really fast. This book was released right after the OceanGate accident, and I was wondering if the author acknowledged this, she did shortly at the end. She wrote a longer piece on the OceanGate Titan accident here, for the curious.
The Underworld was one of my favourite 2025 reads. I've read other books by this author and enjoyed all of of them, happy that this was another winner. This is an amazing read, this time about deep sea exploration and submersibles. A good combination of stories, historical research and personal adventures made the pages go by really fast. This book was released right after the OceanGate accident, and I was wondering if the author acknowledged this, she did shortly at the end. She wrote a longer piece on the OceanGate Titan accident here, for the curious.
April 7, 2024
I felt like this book spent to much time on Casey’s friends and adventures rather than really focusing on the Ocean deep. The picture placement should have been through out, as it was annoying to not have see what she was describing until the end of the book. The author’s storytelling was not engaging enough for the topic.
Maybe I made a mistake in thinking this book was something different. I can certainly see how others would like it, especially those who wanted to be oceanographer or deep sea diver, but this book was not entertaining enough for me.
Maybe I made a mistake in thinking this book was something different. I can certainly see how others would like it, especially those who wanted to be oceanographer or deep sea diver, but this book was not entertaining enough for me.
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