Titan submersible implosion

2023 Titan submersible implosion

Date	18 June 2023
Location	North Atlantic Ocean, near the wreck of the Titanic
Coordinates	41°43′32″N 49°56′49″W
Type	Maritime disaster
Cause	Failure of the pressure hull
Participants	OceanGate and passengers
Outcome	Submersible destroyed by implosion
Deaths	5 (see fatalities)

On 18 June 2023, Titan, a submersible operated by OceanGate, an American tourism and expeditions company, imploded during its descent in the North Atlantic Ocean, about 320 nautical miles (590 km) off the coast of Newfoundland, Canada. The submersible, carrying five people, was part of an expedition to view the wreck of the Titanic. Communication with Titan was lost 1 hour and 45 minutes into its dive, and authorities were alerted when it failed to resurface at the scheduled time later that day.

After a search lasting nearly 80 hours, a remotely operated underwater vehicle (ROV) discovered a debris field containing parts of Titan, about 500 metres (1,600 ft) from the bow of the Titanic. The search area was informed by the United States Navy’s (USN) sonar detection of an acoustic signature consistent with an implosion around the time communications with the submersible ceased, suggesting the pressure hull had imploded while Titan was descending, resulting in the instantaneous deaths of all five occupants.

The search and rescue operation was conducted by an international team led by the United States Coast Guard (USCG), USN, and Canadian Coast Guard. Support was provided by aircraft from the Royal Canadian Air Force and United States Air National Guard, a Royal Canadian Navy ship, as well as several commercial and research vessels and ROVs.

Numerous industry experts had raised concerns about the safety of the vessel. OceanGate executives, including its CEO Stockton Rush (one of the fatalities in the implosion), had not sought certification for Titan, arguing that excessive safety protocols hindered innovation.

Background

OceanGate

Main article: OceanGate

OceanGate is a private company, founded in 2009 by Stockton Rush and Guillermo Söhnlein. Since 2010, it has transported paying customers in leased commercial submersibles off the coast of California, in the Gulf of Mexico, and in the Atlantic Ocean. The company is based in Everett, Washington, U.S.

Rush realised that visiting shipwreck sites was a way to get media attention, and in 2016 the company transported customers to a shipwreck for the first time, using their submersible Cyclops 1 to visit the Andrea Doria wreck site. In 2019, Rush told Smithsonian magazine "There's only one wreck that everyone knows ... If you ask people to name something underwater, it's going to be sharks, whales, Titanic".

Titanic

Main article: Wreck of the Titanic

RMS Titanic was a British ocean liner which sank in the North Atlantic Ocean on 15 April 1912, after colliding with an iceberg. More than 1,500 individuals died, making it the deadliest sinking of a single ship at the time. In 1985, Robert Ballard located the wreck of the Titanic on the ocean floor, around 400 nautical miles (740 km; 460 mi) from the coast of Newfoundland. The wreck lies at a depth of about 3,810 metres (12,500 feet; 2,080 fathoms).

Titan submersible

Main article: OceanGate § Titan

OceanGate's Cyclops 1, the predecessor of Titan. Titan had a 380 mm (15 inch) window.

Computer model render of Titan

Titan was a five-person submersible vessel operated by OceanGate Inc. The 6.7-metre-long (22 ft), 10,432 kg (23,000 lb) vessel was constructed from carbon fibre and titanium. The entire pressure vessel consisted of two titanium hemispheres with matching titanium interface rings bonded to the 142 cm (56 in) internal diameter, 2.4-metre-long (7.9 ft) carbon fibre-wound cylinder. One of the titanium hemispherical end caps was fitted with a 380 mm-diameter (15 in) acrylic window. In 2020, Rush said that the hull, originally designed to reach 4,000 m below sea level, had been downgraded to a depth rating of 3,000 m (9,800 ft) after demonstrating signs of cyclic fatigue. In 2020 and 2021, the hull was repaired or rebuilt. Rush told the Travel Weekly editor-in-chief that the carbon fibre had been sourced at a discount from Boeing because it was too old for use in the company's airplanes. Boeing stated they have no records of any sale to Rush or to OceanGate.

A Logitech F710 wireless game controller. A modified version was used to steer Titan.

Titan could move at up to 3 knots (5.6 km/h; 3.5 mph) using four electric thrusters, arrayed two horizontal and two vertical. Its steering controls consisted of a Logitech F710 wireless game controller with modified analogue sticks. The use of commercial off-the-shelf game controllers is not particularly unusual among vehicles such as submarines that need more than just a steering wheel to control.

OceanGate claimed on its website as of 2023 that Titan was "designed and engineered by OceanGate Inc. in collaboration [with] experts from NASA, Boeing, and the University of Washington" (UW). In presentation by Rush, he claimed his teams even shook the building and cause damage, during pressure test of its acoustic system of hull. A 1⁄3-scale model of the Cyclops 2 pressure vessel was built and tested at the Applied Physics Laboratory (APL) at UW; the model was able to sustain a pressure of 4,285 psi (29.54 MPa; 291.6 atm), corresponding to a depth of about 3,000 m (9,800 ft). After the disappearance of Titan in 2023, UW claimed the APL had no involvement in "design, engineering, or testing of the Titan submersible". A Boeing spokesperson also claimed Boeing "was not a partner on the Titan and did not design or build it". A NASA spokesperson said that NASA's Marshall Space Flight Center had a Space Act Agreement with OceanGate, but "did not conduct testing and manufacturing via its workforce or facilities".

According to OceanGate, the vessel contained monitoring systems to continuously monitor the strength of the hull. The vessel had life support for five people for 96 hours. There is no GPS underwater; the support ship, which monitored the position of Titan relative to its target, sent text messages to Titan providing distances and directions.

Titan had seven backup systems intended to return the vessel to surface in case of emergency, including ballasts that could be dropped, a balloon, and thrusters. Some of the backup systems were designed to work even if all aboard the submersible were unconscious, such as sandbags held by hooks that dissolve after a certain number of hours in saltwater. Ideally, this would release the sandbags, allowing the vessel to float to the surface. An OceanGate investor explained that if the vessel did not automatically ascend after the elapsed time, those inside could help release the ballast either by tilting the ship back and forth to dislodge it or by using a pneumatic pump to loosen the weights.

Expeditions to the Titanic

Titan made its first dive to the Titanic in July 2021. In total, OceanGate undertook six dives to the Titanic in 2021 and seven in 2022.

Each dive typically had a pilot, a guide and three paying passengers on board. Once inside the submersible, the hatch would be bolted shut and could only be reopened from the outside. The descent from the surface to the Titanic typically took two hours, with the full dive taking about eight hours. Throughout the journey, the submersible was expected to emit a safety ping every 15 minutes to be monitored by the above-water crew. The vessel and surface crew were also able to communicate via short text messages.

Customers who travelled to the Titanic with OceanGate, referred to as "mission specialists" by the company, paid US$250,000 each for the eight-day expedition.

OceanGate intended to conduct multiple expeditions to the Titanic in 2023, but because of poor weather in Newfoundland, the June expedition in which the Titan was destroyed was the only one the company had launched that year.

Safety and concerns

Safety

Because Titan operated in international waters and did not carry passengers from a port, it was not subject to safety regulations. The vessel was not certified as seaworthy by any regulatory agency or third-party organization. Reporter David Pogue, who completed the expedition in 2022 as part of a CBS News Sunday Morning feature, said that all passengers who enter Titan sign a waiver confirming their knowledge that it is an "experimental" vessel "that has not been approved or certified by any regulatory body, and could result in physical injury, disability, emotional trauma or death". Television producer Mike Reiss, who also completed the expedition, said the waiver "mention[s] death three times on page one". A 2019 article published in Smithsonian magazine referred to Rush as a "daredevil inventor". In the article, Rush is described as having said the U.S. Passenger Vessel Safety Act of 1993 "needlessly prioritized passenger safety over commercial innovation". In a 2022 interview, Rush told CBS News, "At some point, safety just is pure waste. I mean, if you just want to be safe, don't get out of bed. Don't get in your car. Don't do anything." Rush said in a 2021 interview, "I've broken some rules to make [Titan]. I think I've broken them with logic and good engineering behind me. The carbon fiber and titanium, there's a rule you don't do that. Well, I did."

OceanGate claimed that Titan was the only crewed submersible that used RTM, "an integrated real-time health monitoring system". The proprietary system, patented by Rush, employed acoustic sensors and strain gauges at the pressure boundary to analyse the effects of increasing pressure as the watercraft ventured deeper into the ocean and to monitor the hull's integrity in real time. This supposedly would function to give early warning of problems and allow enough time to abort the descent and return to the surface.

Prior concerns

In 2018, OceanGate's director of marine operations, David Lochridge, composed a report documenting safety concerns he had about Titan. In court documents, Lochridge said that he had urged the company to have Titan assessed and certified by an agency, but OceanGate had declined to do so, citing an unwillingness to pay. He also said that the transparent viewport on its forward end was only certified to reach a depth of 1,300 m (4,300 ft), only a third of the depth required to reach the Titanic. Lochridge was also concerned that OceanGate would not perform nondestructive testing on the vessel's hull before undertaking crewed dives, and alleged that he was "repeatedly told that no scan of the hull or Bond Line could be done to check for delaminations, porosity and voids of sufficient adhesion of the glue being used due to the thickness of the hull".

OceanGate said that Lochridge, who was not an engineer, had refused to accept safety approvals from OceanGate's engineering team, and that the company's evaluation of Titan hull was stronger than any kind of third-party evaluation Lochridge thought necessary. OceanGate sued Lochridge for allegedly breaching his confidentiality contract and making fraudulent statements. Lochridge countersued, stating that he had been wrongfully terminated as a whistleblower for bringing up concerns about Titan's ability to operate safely. The two parties settled a few months later.

Later in 2018, the Marine Technology Society wrote a letter to Rush expressing "unanimous concern regarding the development of 'TITAN' and the planned Titanic Expedition", indicating that the "current experimental approach ... could result in negative outcomes (from minor to catastrophic) that would have serious consequences for everyone in the industry". A signatory of the letter later told The New York Times that Rush had called him after reading it to tell him that he believed industry standards were stifling innovation.

In March 2018, Rob McCallum, a leading deep sea exploration specialist, emailed Rush to warn him he was potentially risking his clients' safety and advised against the submersible's use for commercial purposes until it had been independently tested and classified: "I implore you to take every care in your testing and sea trials and to be very, very conservative." Rush replied that he was "tired of industry players who try to use a safety argument to stop innovation ... We have heard the baseless cries of 'you are going to kill someone' way too often. I take this as a serious personal insult." McCallum then sent Rush another email in which he said: "I think you are potentially placing yourself and your clients in a dangerous dynamic. In your race to Titanic you are mirroring that famous catch cry: 'She is unsinkable'". This prompted OceanGate's lawyers to threaten McCallum with legal action.

In 2022, the British actor and television presenter Ross Kemp, who had previously taken part in deep sea dives for the television channel Sky History, had planned to mark the 110th anniversary of the sinking of the Titanic by recording a documentary in which he would undertake a dive to the wreckage using Titan. The project was shelved after production company Atlantic Productions deemed the submersible to be unsafe and not "fit for purpose".

Earlier incidents

External videos
CBS Sunday Morning / David Pogue report on OceanGate, broadcast November 27, 2022 (YouTube)

In 2022, reporter David Pogue was onboard the surface ship when Titan became lost and could not locate the Titanic during a dive. Pogue's December 2022 report for CBS News Sunday Morning, which questioned Titan's safety, went viral on social media after the submersible lost contact with its support ship in June 2023. In the report, Pogue commented to Rush that "it seems like this submersible has some elements of MacGyvery jerry-rigged-ness". He said that a $30 Logitech F710 wireless game controller with modified control sticks was used to steer and pitch the submersible, and that construction pipes were used as ballast.

In another 2022 dive to the Titanic, one of the thrusters on Titan was accidentally installed backwards and the submersible started spinning in circles when trying to move forward near the sea floor. As documented by the BBC documentary Take Me to Titanic, the issue was bypassed by steering while holding the game controller sideways. According to November 2022 court filings, OceanGate reported that in a 2022 dive the submersible suffered from battery issues and as a result had to be manually attached to a lifting platform, causing damage to external components.

Incident

The voyage was booked in early 2023. Rush approached Las Vegas businessman Jay Bloom with two discounted tickets, intending for him and his son to be on the trip. The billionaire was offered a price of $150,000 per seat, rather than the full price of $250,000, with Rush claiming that it was "safer than crossing the street". Bloom turned down the offer over safety concerns. At that time the trip was scheduled for May, but bad weather delayed it to June.

MV Polar Prince (seen here in 2018) transported Titan and the expedition's crew to the dive site above the wreck of the Titanic.

Preparations – 16–17 June

On 16 June 2023, the expedition to the Titanic departed from St. John's, Newfoundland, aboard the research and expedition ship MV Polar Prince.

The ship arrived at the dive site on 17 June. One of the occupants, Hamish Harding, posted on Facebook: "Due to the worst winter in Newfoundland in 40 years, this mission is likely to be the first and only crewed mission to the Titanic in 2023. A weather window has just opened up and we are going to attempt a dive tomorrow." He also indicated the operation was scheduled to begin around 04:00 EDT (08:00 UTC).

Dive and disappearance – 18 June

The dive operation began on 18 June at 9:30 a.m. Newfoundland Daylight Time (NDT), or 12:00 UTC. For the first hour and a half of the descent, Titan communicated with Polar Prince every 15 minutes, but communication stopped after a recorded communication at 11:15 a.m. (13:45 UTC). The submersible was expected to resurface at 4:30 p.m. (19:00 UTC). At 7:10 p.m. (21:40 UTC) the U.S. Coast Guard was notified of the missing vessel. Titan had up to 96 hours of breathable air supply for its five passengers when it set out, which would have expired on the morning of 22 June 2023 if the submersible had remained intact.

A U.S. Navy acoustic detection system designed to locate military submarines detected an acoustic signature consistent with an implosion hours after Titan submerged. This information was discovered after the submersible was reported missing, which caused the Navy to review its acoustic data from that time period. The Navy passed the information to the Coast Guard.

Search and rescue efforts – 18–22 June

Rear Admiral John Mauger delivers a press briefing in Boston on 19 June.

Deep Energy (pictured in the Netherlands, 2015) arrived with two ROVs on 20 June.

U.S. Coast Guard HC-130 flying over L'Atalante on 21 June

The United States Coast Guard, United States Navy, and Canadian Coast Guard led the search and rescue efforts. Aircraft from the Royal Canadian Air Force and United States Air National Guard, a Royal Canadian Navy ship, and several commercial and research ships and remotely operated underwater vehicle (ROVs) also assisted in the search. The search involved both a surface search and an underwater sonar search.

Crews from the Northeast Sector of the United States Coast Guard, based in Boston, launched search missions 900 nautical miles (1,700 km) from the shore of Cape Cod, Massachusetts. Joint Rescue Coordination Centre Halifax reported that a Royal Canadian Air Force Lockheed CP-140 Aurora aircraft and CCGS Kopit Hopson 1752 were participating in the search in response to a request for assistance by the Maritime Rescue Coordination Center in Boston made on 18 June at 9:43 p.m. (00:13 UTC). The search on 19 June involved three C-130 Hercules aircraft, two from the United States and one from Canada; a P-8 Poseidon anti-submarine warfare aircraft from the United States, and sonobuoys. Search and rescue was hampered by low visibility weather conditions, which cleared the next day.

The U.S. Coast Guard indicated that the search and rescue mission was difficult because of the remote location, weather, darkness, sea conditions, and water temperature. Rear Admiral John Mauger said that they were "deploying all available assets". While many submersibles are equipped with an acoustic beacon which emits sounds that can be detected underwater by rescuers, Titan did not have such a device.

Passing aircraft were asked to look out for Titan, as seen in this New York Oceanic (KZWY) ATC message, displayed in the cockpit of El Al's Boeing 787-9, 4X-EDL on 20 June.

The pipe-laying ship Deep Energy, operated by TechnipFMC, arrived on site on 20 June 2023, with two ROVs and other equipment suited to the seabed depths in the area. As of 10:45 a.m. (13:15 UTC), the U.S. Coast Guard had searched 10,000 square miles (26,000 km²). The New York Air National Guard's 106th Rescue Wing joined in the search and rescue mission with a HC-130J, with plans for two more to join by the end of the day.

According to an internal U.S. government memo, a Canadian CP-140 Aurora's sonar picked up underwater noises while searching for the submersible. The U.S. Coast Guard officially acknowledged the sounds early the following morning, but reported that early investigations had not yielded results. Rear Admiral John Mauger of the U.S. Coast Guard said the source of the noise was unknown and may have come from the many metal objects at the site of the wreck. A Canadian CP-140 Aurora plane had previously spotted a "white rectangular object" floating on the surface. A ship sent to find and identify the object was diverted to help find the source of the noise. The noises were later described by the U.S. Coast Guard as being apparently unrelated to the missing vessel.

CCGS John Cabot arrived in the morning of 21 June, bringing additional sonar capabilities to the search effort. Commercial vessels Skandi Vinland and Atlantic Merlin also arrived that day, as did a Coast Guard C-130 crew. As of about 3:00 p.m. (17:30 UTC), five air and water vehicles were actively searching for Titan, and another five were expected to arrive in the next 24–48 hours. Search and rescue assets included two ROVs, one CP-140 Aurora aircraft, and the C-130 aircraft.

The U.S. Navy's Flyaway Deep Ocean Salvage System (FADOSS), a ship lift system designed to lift large and heavy objects from the deep sea, arrived in St. John's, though no ships were available to carry the system to the wreck site. Officials estimated it would take around 24 hours to weld the FADOSS system to the deck of a carrier ship before it could set sail to the search and rescue operation.

Despite rising concerns about depletion of air supplies on Titan if it were intact, a U.S. Coast Guard spokesperson said at a press conference that "This is a search and rescue mission 100%", rather than a wreckage recovery mission.

Capt. Jamie Frederick delivers a press briefing in Boston on 21 June.

An Odysseus 6k ROV from Pelagic Research Services, travelling aboard the Canadian-flagged offshore tug MV Horizon Arctic, reached the sea floor and began its search for the missing submersible. The French RV L'Atalante also deployed its ROV Victor 6000, which can reach depths of up to 6,000 m (20,000 ft) and transmit images to the surface.

Discovery of debris – 22 June

Rear Admiral John Mauger delivers a press briefing in Boston on 22 June.

At 1:18 p.m. (15:48 UTC) on 22 June the U.S. Coast Guard's Northeast Sector announced that a debris field had been found near the wreck of the Titanic. The debris, located by Pelagic Research Services' Odysseus 6k ROV five hours into its search, was later confirmed to be part of the submersible. At 4:30 p.m. (19:00 UTC) – at a U.S. Coast Guard press conference in Boston – the Coast Guard said that the loss of the submersible was due to an implosion of the pressure chamber and that pieces of Titan had been found on the sea floor about 1,600 feet (about 500 metres) from the bow of the Titanic.

The identified debris consists of the tail cone (not part of the pressure vessel) and the forward and aft end bells – both part of the pressure vessel intended to protect the crew from the ocean environment. According to the U.S. Coast Guard, the debris field was concentrated in two areas, with the aft end bell lying separate from the front end bell and the tail cone.

Rear Admiral John Mauger of the US Coast Guard said that the debris was consistent with a "catastrophic loss of the pressure chamber". Mauger stated that he did not have an answer as to whether the bodies of those on board would be recovered, but he did say that it was "an incredibly unforgiving environment".

Further mission – 23 June

Pelagic Research Services confirmed on 23 June that a new mission to the Titan debris field was already underway and that it had taken the Odysseus 6k ROV one hour to reach the site to continue searching and documenting debris. It was further reported that the debris from Titan is too heavy for Pelagic's ROV to lift, and that any recovery would need to take place at a later stage.

Ship's return to harbour – 24 June

On 24 June, the Polar Prince returned to St. John's harbour. In their bid to understand what caused Titan's catastrophic implosion, investigators boarded the support ship. Another boat was seen in the harbour towing the launch platform which the Titan used.

Fatalities

This incident resulted in five fatalities:

• Stockton Rush (61), an American submersible pilot, engineer and businessman. He was the chief executive and co-founder of OceanGate.
• Paul-Henri Nargeolet (77), a former French Navy commander, diver, submersible pilot, member of the French Institute for Research and Exploitation of the Sea, and director of underwater research for E/M Group and RMS Titanic, Inc., which owns salvage rights to the wreckage site. Nargeolet led more than 35 expeditions to the wreck, supervised the recovery of thousands of artifacts, and was "widely considered the leading authority on the wreck site".
• Hamish Harding (58), a British businessman, aviator, and space tourist. He had previously descended into the Mariana Trench, broken the Guinness World Record for the fastest circumnavigation of the Earth, and flown into space in 2022 on Blue Origin NS-21.
• Shahzada Dawood (48), a Pakistani-British businessman of the Dawood Hercules Corporation and philanthropist, a grandson of Pakistani industrialist Ahmed Dawood.
• Suleman Dawood (19), the son of Shahzada Dawood, who was a student at the University of Strathclyde.

Investigations

On 23 June, both Canada and the United States announced that they were launching investigations into the incident.

The United States investigation will involve the National Transportation Safety Board and the Coast Guard, the latter of which will take the lead because it declared the incident a "major marine casualty."

The Canadian Transportation Safety Board announced that it had launched an investigation into the incident as Titan's support vessel, MV Polar Prince, is a Canadian-flagged ship. A team of TSB investigators headed to St. John's, Newfoundland—from where the journey began—to "gather information, conduct interviews and assess the occurrence", with other agencies also expected to be involved. The Royal Canadian Mounted Police also announced that it was performing a preliminary examination of the incident in order to determine whether to launch a full investigation.

Reactions

Discussing the scale of the search and rescue response, Sean Leet, co-founder and chair of Horizon Maritime Services, the company that owns Polar Prince, said, "I've been in the marine industry since a very young age and seen a lot of different situations, and I've never seen equipment of that nature move that quickly [...] The response from the U.S. Coast Guard, the U.S. Military, folks at the airport, the people here, various companies who were involved in the mobilization of that equipment [...] it was done flawlessly."

Parks Stephenson, director of the USS Kidd Veterans Museum and Titanic researcher, commented early on about the disappearance of Titan: "No matter what you may read in the coming hours, all that is truly known at this time is that communications with the submersible have been lost and that is unusual enough to warrant the most serious consideration." Stephenson is experienced in deep-sea explorations such as Titan's, having previously dived to view the Titanic on five occasions.

The scale of the search and rescue efforts and media coverage compared to those for the Messenia migrant boat disaster days earlier has sparked criticism. Ishaan Tharoor of the Washington Post wrote that Pakistani internet users compared and contrasted the Pakistani victims in both incidents. In the Ionian Sea off the coast of Pylos, Messenia, Greece, a fishing boat sank while carrying an estimated 400 to 750 migrants, resulting in nearly 100 people confirmed dead, another 100 rescued, and several hundred more still missing. Search and rescue efforts for the migrant ship were conducted by the Hellenic Coast Guard and military.

Chris Boyer of the National Association for Search and Rescue said the search for Titan likely cost millions of dollars of public funds; however, the USCG declined to give an estimate, saying they "do not associate cost with saving a life." The incident renewed past debates about whether taxpayers should bear the cost of search and rescue missions involving wealthy persons engaged in high-risk adventuring, such as incidents involving Steve Fossett and Richard Branson. According to U.S. attorney Stephen Koerting, Federal law generally prohibited the Coast Guard from recovering costs related to searches and rescues at the time of the incident.

According to David Scott-Beddard, the CEO of White Star Memories Ltd, a Titanic exhibition company, the likelihood of conducting future research at the Titanic wreck has decreased due to the loss of Titan.

The submersible became widely discussed on social media as the story developed. The incident inspired Internet memes which ridiculed the submersible's deficient construction, OceanGate's poor safety record, and the victims; some video game modders recreated Titan as a playable vehicle for Grand Theft Auto V, and Roblox users recreated the submersible – often including the event that transpired – as interactive multiplayer games. The memes were criticized as insensitive, with David Pogue commenting that they were "inappropriate and a little bit sick"; the Grand Theft Auto mods also received similarly negative reactions where some fans questioned its timing and appropriateness considering the deaths of those involved. Some have felt the negative reaction to the victims may be a response to past news coverage of other extreme expeditions carried out by billionaires with their own companies, such as SpaceX or Blue Origin. Molly Roberts wrote in the Washington Post that those joking about the incident were demonstrating Internet users' impulses to be ironic, provocative, and angry with each other, combined with an "eat-the-rich attitude".

James Cameron, who directed the 1997 film Titanic, has visited the wreckage site 33 times, and built his own submersible to visit the bottom of the Mariana Trench said he was "struck by the similarity" between the submersible's implosion and the events that led to the Titanic disaster. Cameron criticized the choice of carbon-fibre composite construction of the pressure vessel, pointing out that such material has "no strength in compression" when subject to the immense pressures at depth. He also criticized Rush's real-time monitoring of the submarine's hull as an inadequate solution that would do little to prevent an implosion.

See also

• List of submarine incidents since 2000
• List of shipwrecks in 2023
• Rescue of Roger Mallinson and Roger Chapman – Rescue of two crew of a submersible in 1973, the deepest search rescue in history
• The Wreck of the Titan – Book believed to have predicted the wreck of the Titanic