Editor’s Note (6/23/23): On June 22 the U.S. Coast Guard announced that a remotely operated vehicle found debris from the Titan submersible. OceanGate Expeditions, the company that owns the vehicle, declared that the Titan and all five people onboard were lost. For more on the deep-sea environment where the debris was discovered, read “See How Crushing Pressures Increase in the Ocean’s Depths.”
During a descent to visit the wreckage of the famed Titanic ocean liner, a submersible craft called the Titan went missing with five people onboard. The vehicle lost communications on Sunday in the North Atlantic Ocean, several hundred miles off Newfoundland. On the following Thursday, after days of searches from the air and with remotely operated vehicles on the seafloor, the U.S. Coast Guard announced the discovery of debris from the sub that is consistent with a catastrophic implosion.
All five crew members are assumed to be dead, according to a press briefing and news outlets.
A remotely operated vehicle (ROV) connected to the ship Horizon Arctic “discovered the tail cone of the Titan submersible approximately 1,600 feet from the bow of the Titanic on the seafloor,” said U.S. Coast Guard Rear Adm. John Mauger during the press briefing on Thursday. After finding additional debris, including the other end of the pressure chamber, experts agreed “the debris is consistent with the catastrophic loss of the pressure chamber,” Mauger said. (The pressure chamber, or pressure vessel, is the interior compartment of the submersible, which is designed to withstand the crushing pressure of the deep ocean.)
Rescue teams and anyone following the story seemed to be holding out hope that the crew of five were still alive and able to survive on the 96 hours of oxygen thought to be onboard the sub at its descent. But at the briefing, Carl Hartsfield, a retired U.S. Navy captain and a researcher at the Woods Hole Oceanographic Institution, said the evidence points to an implosion in the water column. And this could have occurred as early as when the submersible lost contact with the surface less than two hours into its excursion. The Titanic shipwreck lies some 12,500 feet beneath the sea surface, where pressures increase to about 375 atmospheres, or the equivalent of 5,500 pounds of force pressing in on every square inch of an object’s surface.
Here’s what to know about the now imploded submersible, the perils of deep-sea exploration and what’s next in the investigation process.
What parts of the submersible did the ROV find?
“We found five different major pieces of debris that told us that it was the remains of the Titan,” said Paul Hankins, director of salvage operations and ocean engineering at the U.S. Navy, during the press briefing. The searchers’ initial find was the nose cone, followed by a large debris field, where they discovered the front end of the pressure hull. “That was the first indication there was a catastrophic event,” Hankins said. In another span of debris, a smaller one, they found the other end of the pressure hull, which “basically comprised the totality of the pressure vessel.”
Did the sub collide with wreckage from the Titanic?
The preliminary answer seems to be no. The ROV found the remains of the Titan sub a far distance from the shipwreck. “That’s off the bow of Titanic,” Hartsfield said during Thursday’s briefing. “It’s in an area where there is not any debris of Titanic—it is a smooth bottom. To my knowledge ... there is no Titanic wreckage in that area.” Hartsfield added that the finding is consistent with the location of the last communication with the sub. “And the size of the debris field is consistent with that implosion in the water column,” he said.
Also consistent with a water column implosion at the time of communication loss is the fact that the sonar buoys that were deployed on Monday did not pick up any sign of an implosion, according to Mauger.
What’s next?
Mauger was leading the search operation, which is complete now, he said at the briefing. Over the next 24 hours, his team will demobilize the nine vessels, medical personnel and other equipment on the scene. “But we’re going to continue remote operations on the seafloor,” he said.
As for whether this catastrophe will lead to an evaluation of safety measures for submersibles, Mauger said, “there’s a lot of questions about why, how, when this happened. And the members of the unified command have those questions, too, as professionals and experts that work in this environment. And this is an incredibly difficult and dangerous environment to work in out there.” (The U.S. Coast Guard, U.S. Navy, Canadian Coast Guard and OceanGate Expeditions, the deep-sea tourism company that operated the Titan, had established a unified command to respond to the incident.)
Mauger said he expects that “questions about the regulations that apply and the standards, that is going to be the focus of future review. Right now, we’re focused on documenting the scene and continuing the seafloor operation.”
What is the Titan, and where did it disappear?
The Titan was a submersible. That means it was a small vehicle used for making excursions from another base craft rather than a submarine that has enough power to get to and from port on its own. The vehicle was about 22 feet long and held a pilot and four passengers—each of whom reportedly paid $250,000 for a ticket to see the famous shipwreck. According to the New York Times, on this expedition, OceanGate CEO Stockton Rush served as pilot, accompanied by French maritime expert Paul-Henri Nargeolet, British businessman and explorer Hamish Harding, and British-Pakistani businessman Shahzada Dawood and his son Suleman.
The Titan had hitched a ride to the Titanic’s resting spot—about 400 miles east-southeast off Newfoundland—with a Canadian research ship called the Polar Prince. The latter ship deployed the submersible on Sunday morning. The Titan was last heard from an hour and 45 minutes after starting its descent.
Remote expeditions like this are inherently dangerous, says Jules Jaffe, a research oceanographer at the Scripps Institution of Oceanography at the University of California, San Diego, who helped find the Titanic in 1985.. “You’re all on your own, so if anything goes wrong, you better have enough safety backups to make sure that you can get back out,” he says.
How common are deep-sea incidents like this?
Jaffe says he doesn’t know of other incidents similar to this one, although the U.S. has lost military submarines before. But there simply haven’t been all that many deep-sea expeditions like the Titan’s to start with. The number of people who have visited depths as low as the Titanic’s resting place probably wouldn’t fill a commercial passenger jet.
What’s it like to make a deep-sea dive in a submersible?
One of the people who has visited such depths is Dawn Wright, an oceanographer and chief scientist at a mapping company called Esri. In 2022 Wright visited Challenger Deep, the deepest point in Earth’s oceans at nearly 36,000 feet below sea level. The Titanic itself lies at a depth of 12,500 feet—still remarkably far down. Even on a fast submersible, the descent is a slow process, Wright says. “It’s a beautiful experience,” she adds. “It’s actually very, very peaceful.”
Wright says submersibles are fully under the control of their pilot, so she herself hasn’t had to do a lot of preparation for her expeditions. This allowed her to focus on scientific observations during the trip to Challenger Deep. “There is a lot to know about the submersible, but there’s not as much as one might think, because you’re putting your life in the hands of the pilot,” Wright says. “You really are a passenger.”
What’s it like at such depths?
At the Titanic’s depth, the ocean is pitch-black and relatively poor in nutrients, so there’s not a whole lot of life or much else to see in most regions, Jaffe says.
The biggest hazard in the deep oceans is the enormous weight of water pushing down on you. Jaffe says that, at the Titanic’s depth, the ocean’s pressure is difficult to comprehend, but he suggests imagining that something massive, like the Statue of Liberty, pressing down on something tiny, like a penny.
“It’s unthinkable,” Jaffe says. “The only reason organisms can survive at that depth is because they’re more or less the same density as the water around them, so they don’t get deformed like us air-breathing creatures.”
What do you need to make a dive like this safely?
Vehicle design is crucial. Deep-sea submersibles are often spherical, or at least their inner chamber is, because the shape helps evenly distribute pressure. Submersibles have traditionally been made of titanium, a particularly strong material, Jaffe says. The worst thing that can happen is for that hull to fail, Wright says. “At those intense pressures, your life ends in a second,” she says. “Everything implodes and you just die instantly.”
Humans on a dive also need oxygen—and the ability to use it efficiently. For instance, Wright says, passengers must be able to stay calm in stressful situations because panicking increases respiration. The vehicle began its expedition on Sunday morning with enough oxygen for five people for 96 hours, but there was no way to monitor at a distance how much oxygen remained. Before the fate of the submersible was known, it was thought that if the passengers could breathe slow and steady, they might have been able to extend the timeline slightly, according to the New York Times. At the time, it was also thoguht that the vehicle’s battery could have also been a factor, according to USA Today, because its power controlled the submersible’s temperature in water that could be only a little above freezing.
The easiest way to control such a the vehicle’s descent and its return to the surface, Jaffe says, is to manipulate its density—for example, with a bladder that can expand and contract. “It’s not hard to get stuff down,” Jaffe says. “Getting the stuff back is the problem.”
Wright says that the communications system is crucial, too. On most of her deep-sea dives, she says, the team sends a robot down first. This helps the submersible navigate and keeps it in touch with the main ship. But Wright says she does not know whether OceanGate used this kind of technology.
It remains largely unclear what safety precautions OceanGate had taken in this situation. Although universities and military organizations operating deep-sea submersibles likely have strict safety and testing protocols, Jaffe says there’s no international regulation of this type of excursion.
How are deep-sea exploration technologies developing?
Deep-sea submersibles are still cutting-edge technology themselves, Wright says, noting that the vehicle she rode was one of only two submersibles in the world that can safely reach Challenger Deep.
“One of the biggest technological advances is this ability to go anywhere in the ocean,” Wright says. “The real advancements are in these vehicles and instruments that can withstand the hydrostatic pressure—it’s the destructiveness of the pressure in the ocean that is a major impediment.”
Within a submersible, battery advances are particularly important. Researchers are also developing better deep-sea lighting systems and mapping technology to support expeditions, she says.
Where could the Titan be, and how are people looking for it?
Editor’s Note: This information dates to when the search was being conducted.
Jaffe says he sees three potential scenarios for the missing submersible. The best-case scenario is that it was able to shed weight and rise to the surface of the water. The vehicle would still be difficult to find, given local weather conditions—on Wednesday, waves were expected to reach nine feet amid low clouds and fog, according to the New York Times—but airplanes flying over might be able to spot it.
The other scenarios are grimmer, Jaffe says. “The best thing would be if they’re on the surface,” he adds. “I think rescue from the seafloor or mid-water is going to be extremely difficult, even if we knew where they were.”
If the Titan is indeed stranded in “mid-water,” or around the middle third of the water column, that would require ships to survey the area using sonar, Jaffe says. Sonar would easily detect anything floating in the water column, he notes, but ships equipped with this technology would move slowly, and they would need to survey a large area of water.
The Titan could also be stuck on the bottom of the ocean. “If they’re sitting on the seafloor, that’s probably the worst news,” Jaffe says. To begin with, there are few vehicles that can reach the Titanic’s depths. Even if the search-and-rescue teams have one, the lost submersible would be difficult to locate—after all, it took several missions to find the much larger Titanic itself in 1985. And the successful expedition needed a week of searching to locate the shipwreck.
If the submersible is on the seafloor, it might blend in with the Titanic’s own debris field, Jaffe notes. “If it’s sitting on the bottom, I don’t know any quick way to find it in a clutter field like the Titanic,” he says.
What is it about the Titanic that inspires such tourism?
The Titanic and its wreckage have long fascinated people, Jaffe says, thanks to its glamour—and the fact that some 1,500 people died when it sank. “It was a monumental ship that we thought was indestructible, and what we found out was that we are still vulnerable to forces on this planet that are beyond our control,” Jaffe says.
That symbolism has drawn people to the site since its discovery, and both Jaffe and Wright say they’re glad to see adventurers take to the deep seas. Wright compares the Titanic shipwreck to a national park on land—places where both science and tourism thrive. “The hope with the Titanic wreck was that it would be more of a sacred site that people would visit, that would be protected from treasure hunters,” Wright says.
“But there’s also great dangers here,” she adds. “It’s like the people who try to climb El Capitan in Yosemite: That’s something that you can do; it’s a wonderful thing to do. But it’s an incredibly dangerous thing to do.”
Editor’s Note (6/22/23): This story was edited after posting to include updated information about the search for the Titan and its implosion. Previosuly, the text was amended on June 21 to include updates on the crew onboard the sub, local weather conditions and concerns about the supplies of oxygen and battery power.