87 HOURS LEFT

Inside the operations room of Canada’s Atlantic-focused Joint Rescue Coordination Centre, or JRCC, in Halifax, Nova Scotia, red lights flashed and an alarm sounded as the call came in. The four men on duty—three from Canada’s Coast Guard, the other from the Royal Canadian Air Force—adjusted their headsets, noted the caller’s number, then “figured out where the lat and long was,” essentially identifying the vessel’s precise position through its coordinates.

The voice—a male’s, sounding “stressed and shocked”— told JRCC operators that a private submersible called Titan had detached from a modified icebreaker called the Polar Prince early that morning, began to descend beneath the waves some 10 hours prior, and had yet to resurface, contrary to its expected return time and dive protocols. That meant the last visual contact with the Titan had been on June 18, 2023, around 9:30 a.m. in the Titan’s time zone. The craft’s integrated communication system that was supposed to allow text messages to travel back and forth to the surface had subsequently stopped working at 11:47 a.m., the same moment that the tracking signal from its acoustic beacon had also vanished from the Polar Prince’s screens.

The Titan’s pilot, Stockton Rush, had cofounded his expedition business, OceanGate, 14 years earlier, chasing an epiphany that he could become a Captain Kirk of the deep through his own private enterprise. His copilot, Titanic historian Paul-Henri Nargeolet, was a former submarine pilot for the French navy who had descended to the Titanic wreck more than three dozen times. They had been joined inside the submersible by a UK-resident father-son pair of dynastic Pakistani wealth, Shahzada and Suleman Dawood, and Hamish Harding, a Hong Kong– and UK-raised British aviation tycoon based in Dubai with several Guinness World Records to his name.

But even if the team had continued with their dive incommunicado, their colleagues on board the Polar Prince knew that the journey down, a tour of the drowned relic, and the return ascent should not have lasted much more than nine hours, putting the submersible back on the surface by roughly 6:30 p.m. Eventually—excruciatingly—that moment came and went, and so OceanGate’s surface team had finally acknowledged the need for outside help and used their onboard satellite phone to call the emergency number for the JRCC.

Their decision initiated an extraordinary multinational search effort across four days, five nations, and six time zones—transfixing the world as the lives of those on board the missing sub seemed to hang in the balance. The incident also trained an unforgiving spotlight on the close-knit world of subsea exploration in an era of high-dollar, high-stakes investment in privately owned underwater vehicles. The details of the search—pieced together from Vanity Fair interviews, emails, and call logs—underline an urgent need for government responsiveness and rescue protocols for the challenges created by the continued expansion of this niche industry.

The JRCC has at its disposal two helicopters and a C-130 Hercules plane on a half-hour standby during daylight hours Monday to Friday, but listening to this distress call, the duty aviation officer immediately understood that aircraft with special subsea acoustic detection capabilities would be needed too. To call up those planes would require approval from the Combined Air Operations Centre in Winnipeg, which he set in motion. He separately requested a so-called staff check at the 14 Wing, Canada’s largest military aviation base on the East Coast, to find out how many pilots and crew were available to launch a surveillance plane from Nova Scotia.

That winter’s weather had been atrocious, and it had remained rough even through May, but by that Sunday in mid-June, there was only a slight swell, two or three feet, and the sky was bright and blue. The Polar Prince had set sail three days earlier from St. John’s, Newfoundland, more than 400 miles northwest of the Titanic site, though much closer than Massachusetts’s Cape Cod peninsula almost a thousand miles to the west. But under a 1979 convention overseen by the UN agency responsible for regulating shipping—the International Maritime Organization, itself born from a framework developed after the 1912 Titanic tragedy—the US Coast Guard’s Atlantic operation, called the First District, was technically responsible for handling the Polar Prince’s distress call. Once the Canadian operator had taken down as much information as was available, he therefore relayed those details to First District headquarters in Boston. Within minutes, the First District’s own on-duty team had dispatched an American C-130 search-and-rescue aircraft from St. John’s, where it happened to be stationed as part of the International Ice Patrol—another multinational vestige of the Titanic disaster.

84 HOURS

Around three hours after the initial distress call, one of the duty officers at the Halifax JRCC contacted their commander, Major Chris Simm, a British Canadian with a decade’s experience saving lives at sea. He was at home, tucking his three daughters into bed, when his cell phone began beeping quietly on a bookshelf. The ultimate search-and-rescue problem, Simm thought to himself: scant information that would require a lot of guesswork.

In 1998, several older colleagues of his had participated in the desperate search for a Swissair flight that had vanished from radar screens. The plane had crashed into a Nova Scotia bay after a cockpit fire, killing all 229 on board. But with an underwater distress case like this, Simm realized, there was no precedent, no playbook, no process. Getting vessels to the site quickly would be difficult, and there were no US military submarines or ships with underwater remotely operated vehicles (ROVs) in the vicinity. As Simm put it, “It’s not something you can just throw into Google and find out.”

81 HOURS

As soon as he landed at JFK around 10:30 p.m. ET that Sunday night, ending a 30-hour journey from Malta via Istanbul, Ed Cassano turned off his phone’s airplane mode and watched it light up with messages. One of them was from a submersible pilot he’d previously worked with, Tym Catterson, who was a safety specialist aboard the Polar Prince, urging him to call back.

A certified diver even before his teens, Cassano had grown up in awe of Jacques Cousteau. He majored in marine biology in college, writing a thesis on international marine law for his master’s at the University of Washington in Seattle, then in short order found himself commanding a research vessel in southeast Alaska for the US National Oceanic and Atmospheric Administration Corps (NOAA). He went on to run the Maritime Museum in Santa Barbara and worked with Cousteau’s son, Jean-Michel, on one of his most high-profile underwater films. In 2013 he cofounded Pelagic Research Services to design, build, and rent out a highly adaptable ROV to scientific groups and businesses that wanted to work in the deepest of seas. By June 2023, he was CEO of a specialized operation that spanned both coasts of the North American continent, collaborating with scientists and companies in the mining and energy industries, as well as government agencies.

A tiny number of companies around the world build and manage submersibles—manned or remotely operated—at extreme depths. Some of these vehicles exist as multimillion-dollar playthings for the super rich, stored on their superyachts; others repair deep-sea oil and gas rigs or focus on furthering scientific advances in rarely visited regions of our planet. Several operate on board a single research vessel called OceanXplorer alongside a range of other advanced tools for marine science. It’s at the heart of a sprawling project called OceanX, underwritten by Ray Dalio, founder of the world’s largest hedge fund. The Connecticut-based billionaire had long been fascinated by the ocean, beginning as a teenage scuba fanatic, but it was during a research trip to the Solomon Islands several years ago—in a submersible surrounded by phosphorescent life-forms—that his decision to invest in a dedicated marine research ship was first solidified.

My visit to OceanXplorer required an hour-long helicopter ride out into the open ocean from one of the Portuguese Azores islands that had once served as a mid-Atlantic way station in the early years of air travel. Bright green fields, sun-bleached stone villages, and vistas of steep volcanoes gave way to pods of whales, their distant blowholes punctuating the shimmering cerulean surface. Titanic director James Cameron helped Dalio design the ship. From the air, it appeared vast, with manned and unmanned submersibles offloading one after another from the flat rear deck. “The way we did it was to go around to all the major oceanographic institutes,” Dalio told me about the vessel prior to the visit, “and ask them what their dreams were: ‘What would you love to have?’ And we put it on it.” OceanXplorer was in the Azores on a mission to prove the value of the marine life around several of the archipelago’s seamounts—massive underwater mountains that rise thousands of feet and serve as a magnet for a dazzling array of fish and marine mammals. At the time of my visit, young Portuguese marine biologists were using a variety of the facilities on board in combinations that might otherwise require years of funding grants and patience, racing to pull together research that would unimpeachably show the local government that large stretches of this region of the Atlantic should be classified as marine protected areas, with respectful limits on local fishing rights. Dalio had financed similar expeditions for years before he commissioned the OceanXplorer, with submersibles and ROVs simply part of a high-priced toolkit that includes a fully staffed media operation, well-stocked laboratories, dozens of diving kits, several smaller speedboats, high-quality onboard cuisine to maintain crew morale, and satellite internet that was fast by midtown Manhattan standards, let alone mid-Atlantic.

A couple thousand miles to the northeast, on the island of Jersey between France and southwest England, I encountered another giant vessel, hulking over a harbor in decidedly less clement climes. Wind and rain lashed the MV Coco as its crew prepared for a voyage to Asia, with a scattering of dedicated storage space for ROVs, towlines, and towering hoists installed on the rear deck. Named for the daughter of Richard Parkinson, a fast-talking Brit with a swirl of strawberry-blond hair who founded the deep-sea specialist business called Magellan, the Coco was a new addition to his global enterprise. Underwater vehicles managed by Parkinson and his various businesses have deployed everywhere from the Russian Arctic to West Africa, contracting with energy companies and mining firms, as well as developing the first underwater 3D scan of the Titanic wreck itself. “We specialize in working with areas where other people can’t,” Parkinson told me in his industrial-chic office above a fish warehouse. “There aren’t many companies that can get past 3,000 meters and sustain operations. We can because we do, all day, every day.”

Scanning his phone, Cassano saw OceanGate’s operations manager, Scott Griffith, had also tried to contact him during the long flight from Turkey. He returned that call too. Griffith laid out the situation, according to Cassano, and added a wrinkle: The Titan submersible had no functioning battery-powered or “passive” tracking system. He also said the Titan’s devices to remove carbon dioxide (known as scrubbers) would provide only enough breathable oxygen for the occupants to survive 96 hours—parameters that Cassano, with his biologist’s brain, would choose to term the window of viability. By the end of the call, with Cassano still deplaning, Griffith had officially hired Pelagic’s ROV 75,000-pound system to help. “I want you to come, I’m activating you,” Cassano recalls him saying. The process to transfer and install all of Cassano’s equipment onto an entirely unknown vessel from scratch could sometimes take up to three months, but if a rescue attempt was to have any chance of success, he recognized, an assistance vessel would have to launch in the next 48 hours. “There’s a clock that has started—long before I got that call,” he recalls thinking. “There are five people who are going to die if we don’t get there.”

70 HOURS

As concern rippled outward from OceanGate, a senior US Navy official phoned Carl Hartsfield at 10:11 a.m. ET the following morning, alerting him to the incident and urging him to turn on a TV set. “The whole community was just coming alive and everybody was calling everybody,” recalls Hartsfield. A former nuclear submarine commander with 30 years’ military service, he focuses these days on autonomous underwater vehicles at the Woods Hole Oceanographic Institution—or WHOI—whose Alvin submersible explored the Titanic site soon after its discovery in 1985. He’d never before heard of OceanGate or the Titan, but he had spent much of his adult life contemplating the possibility of underwater entrapment: “Anytime there’s a submarine down anywhere in the world, all submariners, all submersible people, everybody that’s been at risk under the waves, we all hold our breath.”

When the Russian submarine Kursk sank to the floor of the Barents Sea in 2000 after one of its torpedoes exploded and tore a gash in its 500-foot hull, up to 23 crew members survived the initial blasts. But a freshly elected President Vladimir Putin dithered over accepting outside help, and the sailors eventually succumbed to a lack of oxygen.

Hartsfield showed no such hesitation last summer, racing from WHOI’s headquarters in Cape Cod up to the US Coast Guard’s First District building overlooking Boston Harbor. He helped interpret the information pouring in there, including a call late Monday morning from the US Fleet Forces Command in Norfolk, Virginia, with details of an acoustic anomaly in the Atlantic that had been detected by a secret underwater surveillance system. (A similar signal had been picked up when an Argentinian naval submarine called the San Juan had vanished in 2017. It had taken a British firm 12 months to locate its remains, around 30 miles from its last known coordinates and scattered over a large area of the seafloor by an implosion.) Hartsfield and his scientific colleagues at Woods Hole were unable to obtain those classified underlying readings, but they had access to an alternative, open-source data provider.

More than 4,000 miles south of the Titanic wreck, in a remote stretch of ocean between Africa and South America, a British-controlled volcanic outcrop known as Ascension Island hosts one of only half a dozen acoustic listening posts operated worldwide by a little-known international agency responsible for monitoring nuclear launches. Several years ago, staff from the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization had stationed three hydrophones above the seafloor north of Ascension in a triangle about a kilometer apart. On the morning of Sunday, June 18, that array picked up sound waves from a distant underwater event. Ten-second snapshots of those readings were then snipped up into 30-kilobyte packets of data and fed via satellite to the organization’s headquarters in Vienna. From there, they were disseminated in reports to government clients, including the US State Department. They eventually ended up on the screens of Woods Hole experts, who were wary of offering any immediate analysis. “That one data point was not enough to make a decision on, in my opinion,” says Hartsfield. “Especially when you know that at that time they were racing a 96-hour clock.”

The Navy had assessed that their own readings of the same underwater event were “not definitive,” according to a naval official who spoke anonymously to The Wall Street Journal. And absent conclusive evidence of a catastrophic failure of the Titan’s pressure hull, another anonymous naval official told The New York Times, it would have been “irresponsible” not to persevere with the search. Every decision and action was being passed through the First District chief, Rear Admiral John Mauger, with the safety of dozens of men and women engaged in potentially risky aspects of the search now his responsibility. But Mauger also knew that from the moment a vessel in port received an instruction, it would take more than 30 hours for those orders to take effect on site in the mid-Atlantic. He had a difficult choice to make in no time. “There is a delay between when you say something and when you get the feedback from that decision,” he explained later. “We had that common understanding of what needed to get done, and that common intent, and folks continued to move out across the board.” The details of the acoustic anomaly were not made public.

On that Monday, June 19, the Bahamas-flagged Deep Energy, owned by UK- and Houston-based TechnipFMC, was nine days into a slow chug from Norway to a new project near Mobile, Alabama. Its capabilities include two onboard ROVs that can help oil and gas companies lay 16-inch steel pipes up to 3,000 meters underwater. Captain Ross Macleod heard about some aircraft chatter on the long-range search-and-rescue radio signal, VHF channel 16. Raised in the remote Outer Hebrides islands off Scotland’s northwest coast, Macleod had been at sea since high school, the past 10 years as a skipper. When his operations manager in Texas called to discuss the Titan, he had already planned how his vessel could be put to use. “I knew that we had sufficient wire rope on board with winches, which would be able to reach the bottom,” he remembers. “Immediately I understood that was going to be a useful tool, possibly a method of recovering the vehicle—the sub—if we happen to find it.” Within minutes of getting the green light, Macleod had turned the Deep Energy around and was hurtling toward the Titanic faster than its published top speed. “To be honest, my adrenaline starts pumping by this point,” recalls Macleod in his soft Scottish brogue. “I truly believed that we were a vessel—the best hope, I thought, for those souls at that time.”

Cassano, still at JFK, had ordered an Uber to his brother’s house in North Salem, New York, where he’d left his truck, and coordinated with the team of operators—scattered from Alaska to Texas—he would need to pilot their ROV. Cassano tried to rest there briefly, but sleep made little sense given the circumstances, and he gunned his truck north through the dawn, stopping frequently to join conference calls with OceanGate’s Griffith, Mauger, and other salvage experts from the US Navy.

Pelagic is headquartered inside an old truck maintenance depot in the leafy and clapboard-friendly village of East Aurora, New York. Thunder rolled overhead last summer when I visited the space, filled with a hulking yellow ROV, two strong aluminum grabbing hands at the front and a panoply of cameras affixed around its exterior. Like so many submersibles, it’s named for a figure from mythology, the charming, cunning, can-do Greek king Odysseus. In a typical year, Pelagic operators spend a third of their time at sea, working for half a dozen organizations, including Cassano’s former employer NOAA, whose projects they’ve supported through the mapping, surveying, and sampling of deep-sea coral in the Gulf of Mexico and South Atlantic. But last June, through sheer luck, Odysseus was available and ready for this unexpected deployment. By late afternoon Monday, Cassano himself had made it to Pelagic’s facility, where he found members of a nearby trucking firm, a clutch of colleagues, and even some neighbors helping to load Odysseus onto trucks for its first-ever rescue dive. Soon enough, four semis roared west to Buffalo Niagara International in upstate New York, where authorities cleared them straight onto the tarmac. While they waited to be loaded, Cassano began coordinating with the ship that had been hired in St. John’s, called the Horizon Arctic, to ensure its deck would be ready and its navigation system and power supply would be compatible.

On board the Polar Prince, Griffith had separately reached out to a former OceanGate employee now working for Woods Hole, who had in turn called principle submersible engineer Andy Bowen, who started plugging the names of suitably equipped scientific research vessels into a global map that tracks sea-traffic data. “It was really kind of a trip around the Horn to figure out who we might be able to call into action to help,” Bowen recalled—similar in some ways to another frantic logistical scramble in the frightening era of Dr. Strangelove. Back in 1966, Woods Hole’s Alvin sub had been suddenly called up to help end an extraordinary diplomatic furor, provoked when an American aircraft accidentally dropped an H-bomb off the coast of Spain. The circumstances of the accident had clearly undermined assurances made by US forces that they were not engaged in nuclear logistics on any of the bases they’d leased from Madrid. After 80 days of underwater searching and one failed winch effort, the bomb was eventually recovered without casualties.

As Bowen worked through his mental short list of the dozen or so submersibles worldwide that he knew could safely dive to the Titanic’s depth, the nearest he could find was on board Atalante, a French ship named for the only mythical Greek heroine allowed to join the all-male Argonauts. Bowen knew the vessel usually carried an ROV called Victor 6000, built to descend to 6,000 meters, and so reached out to a longtime friend at Ifremer, the French government agency that oversees the country’s oceanographic efforts. It turned out the Atalante was helping with a geophysical survey in the Azores. But after a flurry of communications between Cape Cod, Boston, Paris, and Brest in northwest France, the Atalante’s captain quickly charted a new course and “put the hammer down,” in Bowen’s words—racing for more than 48 hours northwest toward the Polar Prince in a bid to save one of its own. Paul-Henri Nargeolet, the Titan’s missing copilot, had once overseen Ifremer’s subsea operations, descending to the Titanic wreck several times in the agency’s older submersible, Nautile. Diving the far newer Victor 6000 to any depth would be difficult though, since the 10-man specialist team that usually operated it was not aboard the Atalante. Back at their base in France, they frantically started packing for a mid-ocean rendezvous.

60 HOURS

That Monday evening at Joint Base McGuire-Dix-Lakehurst in New Jersey, Captain Matthew Hahn got a fresh set of orders: There’d be no trip to Germany to pick up service members’ household items. Instead, he’d be making a quick swing through Dover Air Force Base in Delaware in his C-17 Globemaster III to pick up some pallets and an extended forklift system used on military cargo known as a K-loader. Then on to Buffalo, where he would collect heavy but delicate cargo that had never been airlifted. The Odysseus ROV would be difficult to tie down securely without damaging it—but any shift in weight during takeoff could also dangerously upset the aircraft’s trim over a heavily populated area. “None of it was normal, and none of it was what we’d ever seen before,” the senior loadmaster, Technical Sergeant Eric McKinley, recalled. But he and his colleagues had already grasped that Odysseus might be the Titan’s best hope: “We had to make this mission work.”

From the Archive: The Last Descent

Many hours later, as Hahn descended over the rugged Atlantic coastline into St. John’s, the 27-year-old from Virginia concluded it was the worst landing in his two years of flying missions. A 20-knot right-to-left crosswind whipped across the slick and slippery asphalt, the visibility so poor that the ground only flashed into vision with 200 feet left, the lowest altitude at which his instruments would safely permit him to land manually. “I actually saw the lights leading up to the runway first before I saw the runway,” he says. In the cockpit of the C-17 behind him—one of three called upon to help transport the Odysseus and its accompanying equipment—Ed Cassano gripped the armrest as the pilots roared in for the turbulent touchdown. The already exhausted New Jersey crew members crashed at a nearby hotel, not realizing their import in the high-profile rescue until locals approached them the next day at Starbucks and then a grocery store to thank them.

36 HOURS

The St. John’s airport sits on a plain just north of town, with little room for the three vast US military aircraft that had been forced to parallel park there. On Pier 12, the Horizon Arctic’s tracked cranes hoisted 10- and 20-foot containers onto the deck, Pelagic’s engineers deciding their precise positioning—typically a weeklong task—in just minutes. A team of eight welders had worked through the night to ensure that the grillage—a steel base to which the Odysseus’s winch would be attached—was secure. At 8:30 p.m. local time, their blowtorches were still brazing as the last truck arrived from the airport. Cassano had told authorities it might take more than 24 hours to install the equipment, but they turned it around in 8, and after a brief safety inspection, the Horizon Arctic was cleared for departure. The vessel—owned by the same Newfoundland firm as the Polar Prince—had worked with OceanGate over the previous two seasons. Many of those on board, including the captain, knew Stockton Rush personally.

29 HOURS

The Horizon Arctic powered through the narrow entrance of St. John’s harbor by 4 a.m. Wednesday, past abandoned British and French cannon posts, with heavily forested hillsides to the starboard and a craggy windswept outcrop called Signal Hill on its port side. More than 111 years had elapsed since a message had reached the hill’s telegram station announcing that the Titanic had struck an iceberg. Learning this, Cassano felt his neck prickle. Adam Myers, the ship’s captain, instructed his chief engineer to push the engine to its limits, cresting at more than 17 knots to reduce the 400-mile journey to the southern edge of the Atlantic’s Grand Banks by an hour or more. “Every freaking minute was counting,” Cassano recalls, as the Pelagic team began prepping for their final task: the rescue itself.

The plan they had formulated with those on other vessels near the Polar Prince was relatively simple, based on the tools they had available. Encased in the polymer rope of the Odysseus’s miles-long umbilical cord were copper wires that power the vehicle below the surface, as well as fiber optic cables that feed imagery from the 8K cameras. It wasn’t built as a dedicated hoisting line, but the Pelagic team was confident it could lift 20,000 to 30,000 pounds of extra weight from the seafloor. OceanGate’s Scott Griffith, by then transferred from the Polar Prince to the Deep Energy, which was already on-site, had confirmed the Titan weighed around 23,000 pounds. Once the Titan was located and before ascending, Odysseus would maneuver a vast hook—known as a Crosby—and attach it to a shackle point on the Titan’s hull, as well as two beacons in case the prone sub somehow slipped back into the abyss and required relocating.

Given the weights involved, the Deep Energy’s ROVs would also concurrently dive to their maximum depth above the Odysseus, waiting to attach the Titan to the pipe-laying vessel’s far more robust rope and powerful winch, to help ease the burden for the remaining 2,700-meter lift. “We’re going down. We’ll grab them. We’ll come up, we’ll meet the other vehicle,” Cassano explained. “It’ll go get the lift line. Bang. We’ll lift them, we’re out.”

4 HOURS

After a full 24 hours of powering through the Atlantic swell, they reached the site and began coordinating with the Deep Energy, believing those on board the Titan might have only hours remaining. “I’m doing the math in my head,” Cassano recalls. “I know that when we arrive on-site, we probably have—I believe—plus or minus four.” Dozens of decisions, hundreds if not thousands of people, exponentially more phone calls and emails had kept hope alive, but there was now almost no margin for error remaining once the team factored in the time needed for the long descent, actually finding the Titan, and then the final leg up to the surface. “That time just goes so quickly. It was horrible. Every time I looked at the clock, another hour had passed,” said Deep Energy captain Ross Macleod, waking after just two hours of sleep. Nevertheless, “it was a moment of optimism,” as he described it, with his engineers planning how they might reprogram their winch system to make that final hoist even faster, before dragging the Titan up on deck and drilling a hole through its hull to provide oxygen to those inside as fast as possible.

Just before 2 a.m. local time, the Canadian Coast Guard’s Ann Harvey joined the cluster of vessels after its own race from St. John’s with the submersible crew that normally worked on the French Ifremer vessel, the Atalante. A choppy sea and dark fog made it difficult to ferry the 10 French ROV operators and their equipment several hundred feet across to the Atalante. Each of them raced up their ship’s ladder like a “scalded cat,” according to the Ann Harvey’s captain, to begin preparing their vehicle to dive as well. The dozen-strong flotilla began taking instruction on their positioning from the Horizon Arctic at that point; Cassano remembers the Deep Energy’s Macleod handing over responsibility ahead of their last-gasp effort with the words “This is your show.” Skipper Adam Myers was nearby on the Horizon Arctic’s bridge, he and Cassano “locked in” as they worked closely to initiate the delicate process of launching an ROV off a vessel that was rolling and pitching in 12-knot winds, its engines powering multiple vast propellers to maintain a precise position—yard by yard at times—for a secure start to the dive.

3 HOURS

Following several final checks, the Odysseus was lowered off the back and into the water to begin its faster-than-usual plunge to just south of the Titan’s last-known position, to avoid the possibility of actually coming down on top of the missing sub. Inside the white shipping container turned control room perched on the Horizon Arctic’s rear deck, the Pelagic team used several keyboards and controllers to guide the Odysseus, its array of cameras broadcasting images of the darkness up to a wall of screens. Back in Boston, Mauger and the dozens of First District officers held their breath, hoping for the best possible outcome. With the dive underway, Coast Guard commanders requested that ship-to-ship communications protocols change, given the presence of family members on board the nearby Polar Prince. If there were signs of life, Pelagic could immediately broadcast the news on an open channel to get the needed assets into position. But absent that, they must be more circumspect. “If you find something, it does not go over the radio,” Cassano was told.

Odysseus dropped through a powerful midwater current, then, just above the seafloor at a depth of 3,831 meters, came a major setback: Its thrusters unexpectedly failed. After several precious minutes spent trying to restart them, the Pelagic team on the surface began the painful process of winching Odysseus back to the surface, and the Horizon Arctic moved backward away from the last known location. Aware his window of viability was near to closing, a crushed Cassano raced back to the bridge and over VHF channel 74—open to the whole flotilla—relayed this setback to the bridge of the Deep Energy, the de facto coordinating vessel. “Guys, we’re out. We’ve got an issue. We’re gonna pull up, but let’s get the French in. Let’s get them to go ahead of us.”

The team from Atalante was only several hundred yards away and had already started to dive their backup ROV, Victor 6000, taking care not to tangle the umbilicals that connected the two submersibles to their controllers up top. Horizon Arctic and Atalante shifted spots precisely using their dynamic positioning—a complex pas de deux that would allow this potentially lifesaving baton to be passed. As Victor 6000 continued its long descent just to the west, Odysseus roared back to life after a remote reset. “We’re back in the game!” shouted Cassano to Deep Energy—immediately instructing his teammates to redive the final few hundred meters.

Minutes later, back on the Horizon Arctic’s bridge with a radio set in either hand, Cassano was startled out of his concentration by the ship’s second mate calling his name over and over. They needed him back on the deck—his team had found something. Cassano careened once more down seven flights of stairs, taking care not to hit his head on several low beams. He clasped the door to the small space, where the ROV’s pilots, navigator, and comms operator quietly turned to look at him. Beside him on a leather-cushioned bench was Kyle Bingham, OceanGate’s mission director, with Bryan Blake, the Navy’s lead for subsea salvage operations, not far away. Cassano scanned the small sea of faces for a hint of what had happened, then on several screens in front of him saw an image from the camera on Odysseus’s main bow. Through the thick bulbous lens mounted beneath the yellow fiberglass roof and between the dark aluminum arms was, unmistakably, a piece of man-made modern debris.

It was one of five large pieces of the Titan, including the tail cone and two shattered ends of the pressure hull, resting on the seafloor about a third of a mile from the Titanic’s bow. The window of viability had closed, if it had ever even been open. Hours later, the US Coast Guard confirmed the news to a waiting world.