The Underworld

How do you truly see a realm that is dark, pressurized, and largely unmapped? In The Underworld, Susan Casey argues that the deep ocean is not a void but a layered, living underworld whose fate is tied to yours. She contends that to grasp its importance—and to decide how we use or protect it—you have to combine three lenses at once: the science that reveals how it works, the machines and people that go there, and the ethics and politics that govern what happens next.

You learn the deep’s vertical geography (twilight, midnight, abyssal, hadal zones), the tools that make it visible (manned submersibles like Alvin and Limiting Factor; robots like Jason and REMUS; cabled observatories like the RCA), and the cultural arc that moved us from monsters to methods (Olaus Magnus’s Carta Marina to HMS Challenger). You then meet modern aquanauts—from Terry Kerby and Alvin pilots to Victor Vescovo’s private hadal program—who show you both brilliance and risk. Finally, Casey takes you into hydrothermal worlds and the twilight zone’s carbon engine before forcing hard choices about seabed mining, shipwreck patrimony, and who gets to decide the deep’s future.

A layered world with planetary stakes

Casey centers four bands: a dimly lit twilight zone (∼600–3,300 feet), a fully dark midnight zone (∼3,300–10,000 feet), the broad abyss (∼10,000–20,000 feet), and the trenches of the hadal (∼20,000–36,000 feet). Each band feels different—light, pressure, and life shift dramatically—and each one performs services you rely on. In the twilight zone, daily vertical migrations move carbon to depth at a planetary scale; on the abyssal plains, sediments form climate archives; in the hadal trenches, unique biology persists under crushing pressure. These are not sterile places; they are engines and libraries.

Seeing in the dark: maps, subs, and cables

Bathymetry—the ocean’s topography—turns guesswork into maps. Multibeam sonar on ships like Pressure Drop revealed vast features during the Five Deeps mapping, just as the MH370 search exposed hidden mountains (Diamantina Trench, Geelvinck Fracture Zone). Manned submersibles (Alvin; Triton’s Limiting Factor) and ROVs (Jason) then turn maps into close-up encounters—sampling vents, tending cabled instruments, and piloting through lava pinnacles. The Regional Cabled Array (Deb Kelley’s project) connects Axial Volcano and the Cascadia margin to shore with fiber, streaming vent chemistry and earthquake data in real time. Suddenly the abyss is a monitored system, not just a destination for occasional expeditions.

From monsters to methods—and the people who go

Our mental map evolved from Leviathans to Latin names. Edward Forbes’s azoic hypothesis declared deep waters lifeless, until systematic dredging and the HMS Challenger reports overturned it with thousands of new species. Human descents—Beebe’s Bathysphere spectacles, Trieste’s first touch of Challenger Deep (Don Walsh and Jacques Piccard), the professionalization embodied by Alvin and HURL’s Pisces IV/V (piloted by Terry Kerby)—made the deep experiential. In Casey’s telling, modern success is not a single hero but a team sport: pilots, engineers, scientists, mappers, and logistics experts who train for fires, entanglement, and runaway oxygen, and who rehearse failure like astronauts.

Worlds without sun—and why they matter

Vent ecosystems rewrite your definition of habitability. At Axial Volcano and Endeavour, black smokers build sulfide chimneys fed by magma-heated fluids, while Lost City’s towering carbonates run on alkaline chemistry from serpentinization. Here, microbes power food webs via chemosynthesis; tubeworms, clams, and shrimp host symbionts like farmers. These sites test origin-of-life hypotheses and serve as analogs for alien worlds (compare to Nick Lane’s work on life’s energetics). With Jason and Alvin swapping sensors on the RCA, you watch vents awaken, evolve, and sometimes collapse—life and geology braided in real time.

Power, money, and who owns the deep

Casey shows you competing models of exploration. Private ambition built a full-ocean-depth system (Vescovo’s Limiting Factor) that delivered repeated hadal dives and mapped 1.2 million square miles. Yet the same private capital raises hard questions: secrecy vs openness, firsts vs shared seats, and what counts as public good. The San José shipwreck saga (Roger Dooley, Presidents Santos and Duque, Odyssey Marine) crystallizes the dilemma: is the seafloor a scientific archive or a marketplace? Meanwhile, seabed mining proposals in the Clarion-Clipperton Zone test whether the International Seabed Authority can protect biodiversity or will bless extraction before we understand the damage.

Key idea

You cannot separate wonder from governance. The same technologies that reveal new life also enable exploitation. What you choose—moratoria, museums, open data, or fast extraction—will shape the underworld for centuries.

Why people still go

Casey insists that human presence changes outcomes. Pilots like Patrick Lahey, Buck Taylor, and Tim Macdonald argue that a person in the sphere perceives nuance and context no camera can. OceanX’s patron Ray Dalio funds subs because awe creates advocates (think of James Cameron’s “no kid dreams of being a robot”). On Kama‘ehuakanaloa (Lō‘ihi), Casey pairs piloting with cultural stewardship, seeking guidance from kupuna Pualani Kanaka‘ole Kanahele—a model for exploration that is not just technically excellent but ethically grounded.

Casey arms you with a working language of the deep so every subsequent scene makes sense. Four zones—twilight, midnight, abyssal, and hadal—signal both depth and experience: fading light, rising pressure, shifting biology. Machines define how you enter each: manned submersibles for immersive, high-skill work; ROVs for tethered precision; AUVs for autonomous surveys; and fiber-optic cables for continuous sensing. Bathymetry, the art of turning echoes into maps, stitches it all together.

How the zones feel (and why that matters)

The twilight zone (∼600–3,300 feet) is neither day nor night. Creatures use light as language—counterillumination, lures, red-light hunting—while daily migrations shuttle carbon into the deep. The midnight zone (∼3,300–10,000 feet) erases surface cues; bioluminescent flashes and drifting snow dominate. At abyssal depths (∼10,000–20,000 feet), vast plains and seamounts host slow-growing life and archive climate in sediments. The hadal (∼20,000–36,000 feet) carves trenches like Mariana and Tonga, with pressure so intense you must engineer perfection. Knowing this helps you read scenes: when Limiting Factor slips into Horizon Deep or Alvin approaches a smoker, you can picture the physics and biology in play.

Vehicles: matching tools to tasks

Casey distinguishes submarines (military, long-endurance) from submersibles (compact, mission-focused). Manned submersibles—Alvin, Pisces IV/V, Limiting Factor—put eyes and judgment on site. ROVs like Jason, tethered to a ship, excel at intricate manipulation and long duration; on the RCA cruise, Jason swapped sensors, brushed biofouled cables, and lifted heavy gear. AUVs like REMUS preprogram surveys for photomosaics and bathymetry—key to the San José site’s 104,000 photos. The hybrid future is already here: humans and robots coordinate, and cabled arrays give you a 24/7 feed (compare to NASA’s Deep Space Network for planetary missions).

Bathymetry: making the invisible legible

Multibeam sonar paints the seafloor with sound. During the Five Deeps, shipboard mappers used hull-mounted arrays and careful sound-velocity profiles to pinpoint exact deepest spots—critical in trenches where slopes and infill shift true minima by tens of meters. In the MH370 search, survey lines unveiled mountain chains and fracture zones (Diamantina, Geelvinck) previously guessed at from sparse data. Once you see the map, you can plan safe approaches, choose science targets, and avoid entanglement hazards (a prime fear for any pilot).

Operational reality: spheres, foam, and fail-safes

Pressure hulls must be spherical and flawless. Syntactic foam provides buoyancy without crushing; ballast systems allow controlled ascent even after failures. HURL’s Pisces subs, certified to ∼6,600 feet, show how careful vetting and redundancy keep crews safe. Alvin’s decades-long upgrades (new titanium sphere, expanded depth rating) reflect institutional discipline. Limiting Factor, engineered for full-ocean depth, embodies bespoke solutions: a precision-machined titanium sphere pressure-tested in Russia; DNV-GL class certification; and robust emergency procedures. On deck and in control vans, crews rehearse fires, oxygen runaways, and cable snarls so they can act calm when the ocean tests them.

Why this foundation matters

When you later weigh policies—mining codes, patrimony laws, or moratoria—you’ll know what is technically feasible, what is risky, and what data streams exist. You move from imagination to measurable reality.

From episodic to continuous observation

The biggest shift Casey documents is continuity. The Regional Cabled Array wires Axial Volcano and Cascadia’s margin for power and data. Seismometers, hydrophones, chemistry probes, and profilers transmit live, enabling volcano forecasts and methane seep monitoring without waiting for ship time. ROVs and subs will still visit; but now the abyss can text you when it hiccups. That is how a frontier becomes a living laboratory.

Casey tracks how our stories about the deep turned from demons to data—and how human rides in small spheres accelerated the shift. The tale starts with fear, pivots to classification, then matures into professional, team-based exploration that blends engineering with science and showmanship with rigor.

Monsters filled the map we didn’t have

Olaus Magnus’s 1539 Carta Marina plastered northern seas with sea orms, Ziphius, and tentacled nightmares. The map’s authority turned gossip into cartography. In absence of observation, myth rushed in. That reflex persists: when we can’t see, we imagine—and often misjudge. (Note: This is the same cognitive gap The Demon-Haunted World warns about; Casey gives you its maritime version.)

From taxonomy to trawls: science enters

The Enlightenment reined in the beasts. Linnaeus’s binomials replaced “sea monsters” with Orcinus orca and friends, allowing accumulation of comparable observations. Still, respectable error lingered: Edward Forbes’s influential azoic hypothesis declared deep waters lifeless below ∼300 fathoms. Systematic dredging and the HMS Challenger (1872–1876), led by Wyville Thomson and Murray, proved otherwise, documenting thousands of species and complex seafloor forms in fifty volumes. Evidence displaced speculation.

First eyes below: Beebe, Barton, and spectacle

William Beebe and Otis Barton’s Bathysphere, hoisted by cable off Bermuda in the 1930s, offered the first human gaze into the midwater dark. The steel ball with fused quartz windows produced vivid descriptions of bioluminescence and strange fishes. Beebe’s identifications drew some academic pushback, but his broadcasts captivated the public, proving that storytelling could fund and popularize inquiry—a theme Casey reprises with OceanX and Five Deeps.

Trieste and the hadal threshold

Auguste Piccard’s bathyscaphe concept evolved into Trieste, which Jacques Piccard and U.S. Navy Lieutenant Don Walsh piloted to Challenger Deep in 1960. Gasoline for buoyancy, iron shot for ballast, and a small pressure sphere carried them to the ultimate abyss. The descent was creaky and the view limited, yet the achievement reset what humans could attempt and measure. Walsh’s professionalism—calm, methodical, trained—set a standard: fear is an operational variable to manage, not a veto.

From dare to discipline: Alvin and HURL

With Alvin, the U.S. built a long-lived, certified science sub. Its pilots and engineers (like Drew Bewley) practice redundancy, testing, and continuous upgrades; it is an institution as much as a vehicle. Terry Kerby’s work at the Hawaii Undersea Research Lab (Pisces IV and V) shows the modern aquanaut’s craft: life-support tradeoffs, ballast jettisons, and entanglement avoidance, mixed with daily swims and years of maintenance. The romance of “firsts” meets the reality of procedures and teams.

People matter—and they train for failure

Casey highlights culture: buck stops with pilots who drill for fires, runaway oxygen, battery faults, and stuck lines. Buck Taylor weeds out overconfident trainees. Tim Macdonald climbs from 1,000-meter certs to full-ocean-depth piloting through staged emergencies and mentorship. This is expedition psychology 101: you select for calm judgment, rehearse the worst, and earn trust incrementally—a template as valid for spaceflight as for hadal diving.

Human lesson

Culture lags observation. Our tools shrink the unknown, but our stories catch up more slowly. Bringing people into the dark—physically—helps the stories evolve with the data.

By the time you reach Five Deeps and OceanX in Casey’s narrative, you recognize a continuum: monsters to methods, spectacle to certification, solo feats to systems engineering. The lesson is not that myth dies; it evolves into wonder, purpose, and a mature respect for risk managed by competent teams.

Hydrothermal vents are the book’s most mind-expanding revelation: thriving ecosystems that run on chemical energy, not sunlight. Casey uses Axial Volcano, Endeavour, and the Lost City to show you how geology, chemistry, and biology braid into living towers—and how new infrastructure like the Regional Cabled Array lets you watch them breathe in real time.

How a vent works

Seawater percolates into cracked ocean crust, heats near magma, dissolves metals and chemicals, then jets back up. In sulfide-rich sites, the hot fluids meet cold seawater to precipitate black smoker chimneys that can grow into giants (think Godzilla or El Guapo at Axial). At the Lost City on the Atlantis Massif, alkaline fluids from serpentinization build towering carbonate spires. In both cases, microbes perform chemosynthesis—oxidizing hydrogen sulfide or hydrogen and methane—to make sugars. Animals like tubeworms, giant clams, and eyeless shrimp host these microbes as endosymbionts or cultivate them like farmers.

Alien biology, here and now

Alvin and Jason dives reveal creatures that force you to rethink physiology: Riftia tubeworms with no mouths, scale worms armored for turbulence, Dumbo octopuses finning through blackness, and glass sponges building delicate cathedrals. Lost City’s archaea survive on geologic hydrogen, and the site’s long-term stability (centuries to millennia) makes it a prime analog for early Earth life (compare to Nick Lane’s alkaline vent hypothesis). The chemistry produces abiotic hydrocarbons, raising tantalizing questions about life elsewhere (Europa-like worlds) and the metabolic scaffolding for the first cells.

Real-time ocean: the RCA at work

Deb Kelley’s Regional Cabled Array strings power and fiber across the Juan de Fuca plate. It anchors seismometers, hydrophones, chemical sensors, and profilers at Axial Volcano and Cascadia margin seeps, piping data to shore 24/7. On RV Atlantis, Casey watches Jason crews replace balky deep profilers, brush biofouling off cables, and tune sensor arrays while bioluminescent siphonophores drift by. You move from snapshots to time series: instead of hoping to witness a vent pulse during a two-week cruise, you listen continuously and then send Jason or Alvin when something spikes.

Why this matters beyond curiosity

Vents are more than spectacles. They host extremophiles whose enzymes could become molecular tools, offer templates for abiogenesis research, and influence regional carbon and sulfur cycling. They also sit near mineral riches—seafloor massive sulfides—that industry eyes hungrily. Nautilus Minerals’ failed Solwara 1 project in Papua New Guinea proved both the technical plausibility of extraction and the social/environmental blowback when communities and ecosystems are discounted. Conservation and curiosity now collide at chimneys built molecule by molecule.

Conceptual shift

Sunlight is optional. Once you accept that chemistry can power abundant life, you expand your search images—for Earth’s deep past, for modern biotechnologies, and for life beyond our planet.

Fieldcraft and fragility

Jason’s manipulator arms can pluck a tubeworm; Alvin’s pilots can hover inches from a chimney lip. But chimneys fracture easily, and microbial mats shear under thrusters. Crews balance curiosity against harm, use low-impact sampling, and mark sites to avoid repeat disturbance. The RCA’s eyes cut down on unnecessary visits. If you care about leaving options open—for science, for evolution—the operational ethic becomes as important as the discovery itself.

Casey makes the mesopelagic—the twilight zone—feel like the ocean’s beating heart. This dim band, roughly 200–1,000 meters, hosts the largest fish biomass on Earth and powers a nightly commute that moves carbon down the water column at a planetary scale. It’s mesmerizing to watch and critical to keep intact.

A city of light in the dark

Descend in a sub like Neptune or Limiting Factor and you drop into a galaxy of bioluminescent signals. Bristlemouths (arguably the most abundant vertebrate on Earth), lanternfish, hatchetfish, viperfish, and dragonfish speak in photophores. Some, like the stoplight loosejaw, exploit red light invisible to most prey; others counterilluminate to vanish from predators below. Jellies and siphonophores form living chandeliers. The spectacle is not decoration; it’s the operating system for feeding, mating, and stealth in a light-starved world.

The great migration

Every dusk, billions to quadrillions of animals rise toward surface waters to feed, then sink back before dawn—arguably the largest daily migration on Earth. This conveyor shuttles carbon: plankton eaten near the surface become fecal pellets and respired CO2 at depth. Casey cites estimates near 4.4 billion tons of carbon transported annually—comparable to major nations’ emissions. This is the biological pump in action, the ocean’s quiet subsidy to climate stability.

Why nets and numbers mislead

Nets undercount agile, light-sensitive fishes that dodge mesh by reading pressure waves and light. That’s why early biomass estimates were low and why new acoustic and optical methods keep revising numbers upward. When industry prospectuses talk about “underutilized biomass” for fishmeal and oils, they often ignore both sampling bias and carbon services. Norway and Pakistan have tested mesopelagic fisheries; Casey warns that scaling this up without robust science risks collapsing a climate function you can’t easily replace.

Personal awe, policy caution

Casey’s own twilight dives leave her grief-struck when the sub must rise—a signal that seeing transforms values. Buck Taylor and other pilots say the human sensory context—color, movement, stillness—cements commitment. That’s not sentimentality; it’s a policy lever. When people in power have felt the blue and watched the lights, they treat the twilight zone as a trust to defend, not a bank to drain.

Governance takeaway

Protect function, not just stocks. Management must value carbon sequestration and biodiversity before approving any industrial harvest of mesopelagic life.

Your stake in the middle sea

If you care about climate, the twilight zone is not optional infrastructure. It buys you cooler summers and fewer extremes by burying carbon. Policies that seem technical—fisheries quotas, gear types, bycatch rules—become planetary. Meanwhile, storytelling and access (subs, films, museums) convert abstract functions into public will. That’s the transformation Casey is trying to spark.

Who gets to go deep, and who decides what they bring back? Casey explores the rise of private, high-spec exploration alongside hard questions about science access, secrecy, and patrimony. Victor Vescovo’s Five Deeps expedition is the engineering exemplar; the San José shipwreck saga is the legal and ethical crucible.

Five Deeps as a startup at sea

Vescovo paid Triton to build Limiting Factor, a full-ocean-depth sub, and acquired the ship Pressure Drop to chase the deepest points in every ocean. Patrick Lahey and designer John Ramsay delivered a titanium-sphere vehicle certified by DNV-GL; Alan Jamieson led science, Rob McCallum ran logistics, and a tight crew (Buck Taylor, Tim Macdonald, Tony Magee, David Lombardo) executed repeated hadal operations. They mapped 1.2 million square miles, fixed failures on the fly (from cracked structures to a battery thermal event at Horizon Deep), and proved that you can run a reliable hadal program if you treat it like aerospace.

Risk and reward, openness and control

Casey shows the tension: “firsts” and records versus seats for scientists; proprietary coordinates to deter looters versus open data; celebrity dives versus methodical sampling. The expedition produced unique bathymetry and hadal footage and advanced lander methods. But critics asked whether tens of millions might have funded cabled observatories or wider community access. The answer is not simple; private systems can leapfrog capability but need norms of inclusion and data sharing.

San José: a wreck as a mirror

Archaeologist Roger Dooley chased the 1708 Spanish galleon San José through archives in Seville and field surveys using REMUS AUVs. His team produced a 2,000-page report and 104,000 photos—then hit legal headwinds. Columbia’s President Santos briefly opened a path to a hybrid model (sell nonpatrimonial coins to fund a Cartagena museum and conservation), only for President Iván Duque to declare the entire wreck patrimonial. Past disputes (Sea Search Armada’s claims; Odyssey Marine’s court losses to Spain) haunted the case. The dilemma is raw: is history best preserved by state stewardship without funds, or by careful, partially commercial partnerships that risk commodification?

Who owns the deep?

International waters complicate everything. The Law of the Sea imagines the seabed as “the common heritage of mankind,” but practice fragments into national EEZs, sponsoring states, contractors, and, in the ISA’s case, even a possible state-run “Enterprise.” In trenches and on wrecks, secrecy protects sites from looters but can also shield private priorities from scrutiny. Casey doesn’t offer a single fix; instead she insists you see the trade-offs and demand governance that rewards science, transparency, and cultural respect.

Ethical hinge

Access without accountability is extraction; protection without resources is neglect. Sustainable exploration lives in the space between—shared standards, open data, funded conservation, and local voices at the table.

When you evaluate future ventures—hadal dives, heritage recoveries, or commercial surveys—ask Casey’s implied questions: Who benefits? Who decides? What data are public? What cultural permissions exist? The answers decide whether the underworld becomes a commons of knowledge or a private frontier.

The same sonar and robotics that reveal beauty also expose value—metals in nodules and sulfide deposits. Casey’s treatment of deep-sea mining is a cautionary history and a policy brief: the economic story is seductive, the ecological story is unfinished, and the governance story is wobbly.

A brief history of appetite

John Mero’s 1960s vision of seabed wealth ignited corporate dreams. The CIA’s Glomar Explorer masqueraded as a mining ship while grabbing a Soviet sub, muddying perceptions. Nautilus Minerals pushed the first commercial seafloor massive sulfide project (Solwara 1) in Papua New Guinea; by 2019 it was bankrupt, leaving debts, gear, and disillusioned communities. Today, The Metals Company (formerly DeepGreen) pitches Clarion-Clipperton Zone (CCZ) nodules as “green” feedstock for batteries, sponsored by small Pacific nations like Nauru and Tonga under the International Seabed Authority (ISA) framework.

How the ISA works—and doesn’t

The ISA, birthed by the UN Convention on the Law of the Sea, grants contracts and is tasked with protecting the marine environment. Its Legal and Technical Commission reviews plans; member states sponsor contractors; and the treaty even envisions an ISA-run mining branch (“the Enterprise”)—a built-in conflict of interest. In 2021, Nauru triggered a two-year rule forcing completion of exploitation regulations, effectively imposing a corporate clock on global governance. Critics say the ISA leans pro-extraction and lacks the data, transparency, and enforcement capacity to safeguard abyssal ecosystems.

What science actually shows

Abyssal plains are not deserts. CCZ surveys report up to 90% novel species in samples; sediments archive climate history in layered time. Disturbance experiments from the 1970s–1990s revisited decades later show painfully slow recovery: tracks still visible, microbial functions depressed, biodiversity altered. Nodules themselves are living real estate for animals that anchor to them; remove the nodules and you erase habitat formed over millions of years. Plumes from collectors can spread silt and metals far beyond lease blocks, with unknown consequences for filter feeders and biogeochemistry.

Green claims, gray zones

Proponents argue nodules avoid deforestation and child labor associated with some terrestrial mines and can decarbonize supply chains. Casey counters that “green” requires full life-cycle accounting: biodiversity, carbon sequestration, sediment archives, and indigenous rights are not externalities you can write off. The precautionary principle—“Just stop. Just wait,” in Sylvia Earle’s words—applies when unknowns dwarf certainties. Moratoria by countries and companies are growing, reflecting rising public skepticism.

Policy bottom line

No exploitation without independent baseline data, public transparency, enforceable safeguards, and clear evidence that ecological harm is acceptable—and reversible. Right now, we lack all four.

What you can insist on

Demand open data from contractors, independent monitoring, plume science before permits, and benefit-sharing that isn’t extractive for sponsoring states. Support moratoria until the science, law, and technology catch up. If the abyss is the planet’s last relatively intact carbon-capturing system, protecting it is climate policy—not niche conservation.

Do you still need people in small spheres when robots can go everywhere? Casey’s answer is yes—and not just for romance. Human presence adds context, judgment, and empathy that shape science and policy. The future is hybrid: subs plus robots, plus a commitment to cultural respect and storytelling that moves publics and presidents.

What a pilot adds that a robot can’t

Pilots make second-by-second calls in environments no algorithm fully models: threading through Titanic’s debris, hovering over fragile chimneys, or skirting entangling ropes. Patrick Lahey likens witnessing a dive to attending a birth rather than watching a recording; the sensory richness leads to better decisions and deeper care. In the twilight zone, Buck Taylor’s insistence that awe matters is not indulgent—it’s a route to durable stewardship.

OceanX and the power of platforms

Ray Dalio’s OceanX fused science with storytelling on ships like Alucia, enabling Blue Planet II sequences and the first giant squid footage. By pairing scientists with filmmakers and subs, OceanX created a pipeline from discovery to public imagination to philanthropy and policy. James Cameron’s line—“No kid ever dreamed of growing up to be a robot”—captures why manned programs pull young minds into STEM and conservation.

Kama‘ehuakanaloa: doing science with respect

Before diving the submarine volcano southeast of Hawai‘i Island, Casey and the crew sought blessing from kupuna Pualani Kanaka‘ole Kanahele, who shared the name and lineage of Kama‘ehuakanaloa (the Red Child of the Deep). The mission then combined meticulous bathymetry (Tomer Ketter), targeted microbiology (Glazer on iron mats), and careful piloting (Vescovo, Macdonald) with cultural stewardship. That blend—technical excellence plus indigenous consultation—is a replicable standard for any frontier expedition.

The hybrid future

Robots like Jason, Mesobot, Nereid, and Orpheus extend reach and endurance; cabled arrays maintain vigilance. Manned subs supply context and chemistry of the heart. Together they produce better science and stronger narratives. Funding models are diversifying (private patrons like Dalio, Gabe Newell, James Cameron; public investments like Alvin’s refit), widening seats at the table. The task now is to align access with openness: train broadly, publish data, and invite publics aboard through media and museums.

Strategic insight

If you want durable ocean policy, put people underwater and let them return changed—then amplify their stories at scale. Awe is not a luxury; it’s an instrument.

From feeling to policy

Dooley’s archival narrative helped open doors with President Santos; Duque’s reversal shows stories can be unmade too. Explorers Club ceremonies, datasets from Five Deeps, and RCA livestreams all shape constituencies. When citizens and leaders see the deep as living heritage—full of vents, migrations, and memory—they vote, fund, and regulate differently. That is Casey’s final throughline: seeing leads to caring, caring leads to keeping.