What we know about the tourist sub that disappeared on an expedition to the Titanic wreck
A massive search ramped up as authorities probed the North Atlantic for a tourist submarine that went missing over the weekend on an expedition to explore the famous Titanic shipwreck.
As multiple agencies from the U.S. and Canada scoured thousands of square miles of open ocean, authorities announced early Wednesday that underwater noises were detected in the search area, prompting further search operations beneath the surface in hopes of finding their origin. Searches involving ROVs — remotely operated underwater vehicles — had yielded negative results as of Wednesday afternoon, but were continuing in the area where the noises were heard, Coast Guard Capt. Jamie Frederick said at a news conference.
Here's what we know so far about the submersible craft and what may have happened to it.
What happened?
A five-person crew on a submersible named Titan, owned by OceanGate Expeditions, submerged on a dive to the Titanic wreckage site Sunday morning, and the crew of the Polar Prince research ship lost contact with the sub about an hour and 45 minutes later, the U.S. Coast Guard said.
The Coast Guard first alerted mariners about the missing sub Sunday night, saying a "21 foot submarine" with a white hull was overdue and giving its last known position. "VESSELS IN VICINITY REQUESTED TO KEEP A SHARP LOOKOUT, ASSIST IF POSSIBLE," the alert message read.
The sub was lost in an area about 900 miles east of Cape Cod, in the North Atlantic, in water with a depth of about 13,000 feet. It had less than 40 hours of breathable air left as of Tuesday afternoon, Coast Guard officials estimated.
"We will do everything in our power to effect a rescue. ... There is a full-court press effort to get equipment on scene as quickly as we can," Frederick told reporters during a news conference Tuesday, calling the search effort "an incredibly complex operation."
The five people aboard included an operator — later identified as Stockton Rush, the CEO of OceanGate Expeditions — and four mission specialists, a term the company uses for its passengers, who paid up to $250,000 for a seat.
Search and rescue efforts underway
Three more vessels arrived at the search area Wednesday morning, including one with side-scan sonar capabilities designed to create images of large sections of the sea floor, the Coast Guard said in a tweet. That vessel began conducting search patterns alongside at least two others, as multiple military and other agencies worked together under a unified command.
Frederick said Wednesday there were five "surface assets" involved in the search, and another five were expected to join the operation within the next 24 to 48 hours. The team also had two ROVs "actively searching," with several more due to arrive to join the search Thursday.
The U.S. Coast Guard said it had C-130 aircraft searching for the sub, and that the Rescue Coordination Center Halifax is assisting with a P-8 Poseidon aircraft, which has underwater detection capabilities. Canadian P-3s are also involved in the operation and have deployed sonar buoys.
Just after midnight Wednesday, officials said aircraft had detected underwater noises in the search area, and underwater search operations were relocated as a result, though the origin of the noises remained unknown. The sounds were picked up several times Tuesday night and Wednesday morning, according to the Coast Guard.
A remotely-operated vehicle search had yielded "negative results" as of Wednesday afternoon, but officials said the search would continue as U.S. Navy experts analyzed the data initially collected by the Canadian aircraft.
"When you're in the middle of a search and rescue case, you always have hope. That's why we're doing what we do," Frederick told reporters.
"With respect to the noises, specifically, we don't know what they are, to be frank with you. The P-3 detected noises, that's why they're up there, that's why they're doing what they're doing, that's why there are sonar buoys in the water."
News of the vanished submersible and subsequent rescue mission originally broke Monday morning. At the time, Lt. Jordan Hart of the Coast Guard in Boston told CBS News that personnel there were leading the rescue mission, and focusing on waters off Newfoundland in eastern Canada.
The Boston Regional Coordination Center was managing the rescue operation, as the location of the Titanic shipwreck falls within the Boston coordination center's territory, according to a map of jurisdictions along the East Coast of North America.
Search operations continued overnight Monday and into Tuesday, when a pipe-laying vessel arrived in the search area and sent a remotely operated vehicle into the water to search for the sub at its last known location, Frederick said.
By Tuesday, crews from the U.S. Coast Guard, Canadian Coast Guard, U.S. Navy and Air National Guard had collectively searched about 10,000 square miles since the sub vanished, according to the unified command formed by those agencies and the sub's owner, OceanGate Expeditions.
That combined search area is about twice the size of the state of Connecticut, and the subsurface search extended down as far as 2 1/2 miles deep, Frederick said, and he stressed that the search and rescue teams were dealing with an incredibly complex set of circumstances.
"We also have to factor in the ever-changing weather conditions, currents and sea states that expand the search area every hour," Frederick said. "There's an enormous complexity associated with this case due to the location being so far offshore and the coordination between multiple agencies and nations. We greatly appreciate the outpouring of support and offers to provide additional equipment."
He said it would be difficult to describe what a deep-sea rescue operation would look like, if the sub is found in time.
"That's a question that then the experts need to look at what is the best course of action for recovering the sub, but I think it's going to depend on that particular situation," he said.
"Right now we're focused on locating the vessel. But at the same time, if we find this vessel in the water then we will have to effect some sort of rescue," Rear Admiral John Mauger of the Coast Guard said at a briefing Monday. "We're coordinating, reaching out to different partners within the U.S. Navy, within the Canadian armed forces, and within private industry to understand what underwater rescue capability might be available."
Mauger told CBS News that officials will hold onto hope for the sub passengers "as long as there are opportunities for survival."
What do we know about the noises?
Frederick acknowledged that the sounds detected by the Canadian aircraft could be caused by a number of sources.
Carl Hartsfield, an expert in underwater acoustics and the director of the Woods Hole Oceanographic Institution, which is on site at the search area as a consultant, explained that it can be challenging to differentiate between "human sounds" and "nature sounds" coming from beneath the surface.
"The ocean is a very complex place obviously human sounds, nature sounds, and it's very difficult to discern what the sources of those noises are at times," Harstfield said.
"But I can tell you that this team has multiple sensors that are in the area, they're sending data back expeditiously to the best in the world people to analyze that data, and then they're feeding the results of that analysis back to the unified team and they're making decisions," he continued.
Chris Roman, an associate professor of oceanography at the University of Rhode Island, told CBS News "it is possible" that the sounds detected by search aircraft could be coming from the lost submersible.
"Sound travels very efficiently underwater. If people were intentionally making noises within the sub, it's very likely they could be detected with a sound buoy, and that position can be translated into a new search area," Roman said. "And I think that's what the captain said there in that brief" — referring to Frederick's comments in Wednesday's news conference — "so that is encouraging. He also mentioned that there's a lot of other things in the ocean that make noises."
The missing submarine
The unique submersible craft that disappeared is owned by OceanGate Expeditions, a company that deploys manned submarines for deep sea exploration and has in the past advertised this particular sub's voyages to carry tourists down to the wreckage of the RMS Titanic for $250,000 per seat.
More than a century after the Titanic sank in April 1912, the wreck lies on the ocean floor about 400 miles southeast of the Newfoundland coast.
OceanGate said recently on its website and on social media that its expedition to the shipwreck was "underway," describing the seven-night trip as a "chance to step outside of everyday life and discover something truly extraordinary." In addition to one ongoing expedition, the company had planned two others for the summer of next year, according to the site.
Because of the sub's oxygen capacity, it can only be fully submerged for a portion of the weeklong voyage. The sub has emergency oxygen and a 96-hour sustainment capability if there's an emergency aboard, Mauger said.
In a statement Monday after news broke of the missing sub, OceanGate confirmed the missing submersible is theirs and that a rescue operation had been launched to find and recover it. The company said it was "exploring and mobilizing all options to bring the crew back safely."
"For some time, we have been unable to establish communications with one of our submersible exploration vehicles which is currently visiting the wreck site of the Titanic," said Andrew Von Kerens, a spokesperson for OceanGate. "We pray for the safe return of the crew and passengers, and we will provide updates as they are available."
Who are the passengers aboard the sub?
CBS News confirmed that the five people aboard the submersible are Hamish Harding, a 59-year-old British billionaire, business owner and explorer; British-Pakistani businessman Shahzada Dawood and his son, Suleman; French explorer Paul-Henri Nargeolet, who has made multiple dives over the years to explore the Titanic; and Stockton Rush, the CEO of OceanGate Expeditions, who was serving as pilot.
Harding's company, Action Aviation, confirmed that he was on the missing sub. "There is still plenty of time to facilitate a rescue mission, there is equipment on board for survival in this event," the company's managing director, Mark Butler, told the Associated Press. "We're all hoping and praying he comes back safe and sound."
Government officials in the United Kingdom told CBS News they are in contact with Harding's family and prepared to assist as search and rescue operations continue.
The Dawood family, of the large Pakistan-based global business conglomerate Dawood Group, issued a statement Tuesday confirming their family members were on the expedition.
"We are very grateful for the concern being shown by our colleagues and friends and would like to request everyone to pray for their safety while granting the family privacy at this time," the statement said. Shahzada Dawood is vice chairman of the Dawood Hercules Corporation, part of the Dawood Group, which the Seti Institute, a nonprofit research organization based in California, said "has been a family business for over a century." Dawood sits on the board of trustees at the Seti Institute, according to its website.
Nargeolet, a renowned French explorer and former diver for the French Navy, who was part of the first expedition to visit the Titanic wreck in 1987, was returning on another dive aboard the now-missing submersible.
In a Facebook post Monday, Rory Golden, an explorer who became the first Irish diver to visit the Titanic wreckage in 2000, said he was part of the voyage but was not on the submersible that went missing.
"I'm OK. We are all focussed on board here for our friends," Golden wrote. "We have a situation that is now the part of a major Search and Rescue effort, being undertaken by major agencies. That is where our focus is right now."
He added: "The reaction and offers of help globally is truly astonishing, and only goes to show the real goodness in people at a time like this."
Who is Hamish Harding?
Harding, the first of the passengers to be publicly identified, had previously posted on social media about joining the Titanic shipwreck expedition.
In a post shared to his Facebook page on Saturday, Harding wrote: "I am proud to finally announce that I joined OceanGate Expeditions for their RMS TITANIC Mission as a mission specialist on the sub going down to the Titanic."
"Due to the worst winter in Newfoundland in 40 years, this mission is likely to be the first and only manned mission to the Titanic in 2023," Harding's Facebook post continued. "A weather window has just opened up and we are going to attempt a dive tomorrow. We started steaming from St. Johns, Newfoundland, Canada yesterday and are planning to start dive operations around 4am tomorrow morning. Until then we have a lot of preparations and briefings to do."
That post was Harding's most recent social media update related to the submarine trip. It included multiple photographs of him, including one that showed Harding signing his name on a banner that read "Titanic Expedition Mission V" and another that pictured the submersible vessel itself.
Richard Garriott de Cayeux, president of The Explorers Club, where Harding helped found the board of trustees, said they spoke last week about the expedition in a letter to club members after the sub's disappearance.
"When I saw Hamish last week at the Global Exploration Summit, his excitement about this expedition was palpable. I know he was looking forward to conducting research at the site," the letter said.
Harding is a veteran adventure tourist who also traveled to space aboard a Blue Origin rocket last year. Two years ago, he made it to the deepest part of the ocean, traveling with U.S. explorer Victor Vescovo to the floor of the Mariana Trench, 35,876 feet below the sea surface. That trip, in a $48 million submersible, earned both explorers the Guinness World Record for the longest distance traveled at the deepest part of the ocean by a crewed vessel.
"It was potentially scary, but I was so busy doing so many things — navigating and triangulating my position — that I did not really have time to be scared," Harding told The Week after that excursion.
What are the options for a rescue if the sub is found?
Even if the monumental search effort is successful, that's only the first step. Rescuing the five people from aboard the sub would be another challenge entirely.
"I think if it's on the seabed, there are so few submarines that are capable of going that deep, and so therefore, I think it was going to be almost impossible to affect a sub-to-sub rescue," Titanic expert Tim Matlin told the Reuters news agency.
Ralf Bachmayer, a professor of marine environmental technology and deep-sea engineering at the University of Bremen in Germany, told CBS News on Wednesday there were two main possibilities for a rescue if the sub is on the seafloor. It could be winched up, which he said would be "very difficult" at the depth in the area, which is around 13,000 feet, or almost two and a half miles. Or rescuers could use a flotation device, called a lift bag, that could be slid under the sub to help lift it to the surface.
Both options would present major, if not insurmountable, difficulties. Matlin said rescuers "can't have a line tethering it all the way down because it would be too heavy and too much drag." Furthermore, the Titan could be entangled in debris, and a flotation rescue attempt would require remotely operated vehicles to gain sufficient access to slide such a device under the 21-foot-long submersible.
"Titanic's wreck is two and a half miles down. It's pitch black down there. It's freezing cold. The seabed is mud and it's undulating. You can't see your hand in front of your face. The only way you can find where you are is by a thing called sonar. Not even radar works," Matlin told Reuters. "It's really a bit like a moon shot. ... So, I do fear for the lives of those explorers who are on board."
"Focus is on the crewmembers"
"Our entire focus is on the crewmembers in the submersible and their families," OceanGate said in its statement Monday, adding that it was "deeply thankful for the extensive assistance we have received from several government agencies and deep sea companies in our efforts to reestablish contact with the submersible."
Before that, the company had last tweeted about its Titanic expedition on June 15.
OceanGate said in a tweet shared earlier this month that it was using the satellite company Starlink to maintain communication with the submersible craft as it journeyed toward the Titanic wreckage.
"Despite being in the middle of the North Atlantic, we have the internet connection we need to make our Titanic dive operations a success — thank you Starlink," OceanGate wrote in the tweet, which it posted alongside an image of the submersible attached to a deck on the surface of the ocean.
The Titan
Dubbed the Titan, OceanGate's deep sea vessel is said to be the only five-person submersible in the world with capabilities to reach the Titanic's depth at nearly 2 and a half miles beneath the ocean's surface, CBS "Sunday Mornings" correspondent David Pogue reported last year.
It is one of three submersible crafts owned by OceanGate that appear on the company's website, BBC News reported, adding that the vessel typically carries a pilot, three paying guests and another person described as a "content expert" by the company. OceanGate's site says the Titan, weighing around 23,000 pounds, has the ability to reach depths of up to 4,000 meters — over 13,000 feet — and has about 96 hours of life support for a crew of five people.
Last summer, Pogue accompanied the Titan crew on the journey from Newfoundland to the site where the Titanic as lost. Several dive attempts had to be canceled when weather conditions indicated it may not be safe. At the time, he described the Titan as a one-of-a-kind submersible craft made from thick carbon fiber and coated on both ends by a dome of titanium.
In 2018, a former employee of OceanGate Expeditions, submersible pilot David Lochridge, voiced concerns about the safety of the Titanic tour sub and filed a lawsuit against the company.
Lochridge, who was fired by OceanGate and sued by the company for allegedly disclosing confidential information in a whistleblower complaint to the Occupational Safety and Health Administration, said in a court filing that the Titan would carry passengers as deep as 4,000 meters even though that depth had never been reached in a sub with its type of carbon fiber hull. According to his claim, he learned the vessel was built to withstand a certified pressure of 1,300 meters, although OceanGate planned to take passengers to 4,000 meters.
Lochridge was not the only skeptic. The same year his complaint was filed, other industry leaders approached OceanGate with questions about the safety of its submersible. William Kohnen, president and CEO of Hydrospace Group, outlined his concerns in a 2018 letter to OceanGate, originally published by The New York Times, that warned of potentially "catastrophic" issues with the "experimental" sub, which was not certified. Kohnen told CBS News on Wednesday that although he did not send it, the letter was leaked to OceanGate and prompted the company to "amend a number of details that made sure the public knew" the submersible had not received its certification.
"The letter to Oceangate was meant as a professional courtesy to the CEO expressing industry concerns that the company was not following a traditional classification route for the certification of the submersible," Kohnen said. "The industry operates along an established and dynamic set of safety regulations and protocols that have served the submersible industry worldwide."
Ahead of his planned dive last summer, Pogue recalled signing paperwork that read, in part, "This experimental vessel has not been approved or certified by any regulatory body, and could result in physical injury, emotional trauma, or death."
Space inside the submarine was similar to the interior of a minivan, and, with just one button and a video game controller used to steer it, the vessel "seemed improvised, with off-the-shelf components," Pogue said.
On his voyage, the sub was lost for a few hours, Pogue said.
"There's no GPS underwater, so the surface ship is supposed to guide the sub to the shipwreck by sending text messages," he reported at the time. "But on this dive, communications somehow broke down."
What could've happened inside
Butch Hendrick, president and founder of Lifeguard Systems — a company that conducts dive training for public safety officers — told CBS News Tuesday that it's possible the Titan had reached the ocean floor when it lost communication. Hendrick speculated the Titan "could have gotten itself entangled somewhere," which could have caused the "communication antenna" to become "dislodged" and "broken," prompting the vessel to lose communication.
Hendrick also explained that it was more likely that the Titan would have "leaked and flooded" rather than imploded. He said that, at the depth of the Titanic's wreckage, the pressure is about 5,000 pounds per square inch (PSI) greater than the pressure at sea level.
"There's no opening a gate, there's no opening a window, there's no making an interactive lock," Hendrick said, adding that a possible leak could potentially impact the submersible's electrical system.
"If that happened, then it may be again that they could still be alive, interior, breathing, and hoping for someone to come and get them," Hendrick said.
Were conditions right for the dive?
G. Michael Harris, founder of RMS Titanic, Inc. — a company that salvages artifacts from the Titanic wreckage — told CBS News on Tuesday evening that Titanic expeditions are generally conducted within a "three-month weather window" between the end of June and September, when the ocean waters are at their calmest.
Harris, who has led several expeditions to the wreckage site, questioned why the Titan's dive was conducted as early as Sunday.
"Right now, it's really early in the season. I'm not sure why OceanGate went out this soon," Harris said.
Harris also noted that when he conducts diving expeditions, he uses a transponder system, something that he believed the Titan likely did not have.
"It's a net that we navigate in so that we know where we are at all times on the wreck of the Titanic," Harris said. "We're in constant communication with the vessel up top."
Harris said the Titan was "put on a sled and dumped in the water and their only navigation is from the support ship up top."
"I don't adhere to that myself, personally," Harris said.
Harris noted that he has worked with Nargeolet, who is listed as director of underwater research for RMS Titanic, for the past 30 years, describing him as an "all-around good guy."
This is an updated version of an article originally published on Monday, June 19. Reporting contributed by Emmet Lyons, Roxana Saberi, Alex Sundby, Aimee Picchi, Aliza Chasan, Li Cohen, Caroline Hinson, Anna Noryskiewicz, Analisa Novak and other CBS News staff.
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