US Coast Guard releases report into Titan submersible implosion

Key takeaways from the Titan sub report

• The sub's carbon-fibre hull failed under immense pressure.
• OceanGate bypassed standard safety practices.
• Workplace culture stifled internal safety concerns.
• Financial pressure led to risky decision-making.
• Stockton Rush’s leadership was a direct factor in the tragedy.
• Authorities urge tighter regulation of deep-sea expeditions.

Report lists 14 recommendations for future safety

To prevent similar tragedies, the report outlines 14 recommendations, including:

• Stronger regulatory oversight of experimental submersibles.
• Revoking "research vessel" status for uncertified commercial operations.
• Mandatory dive plans and emergency protocols.
• The report also suggests that the US Coast Guard (USCG) should have resources dedicated to "providing field support for vessels of novel design".

Stockton Rush’s negligence highlighted in report

The report concludes that OceanGate CEO Stockton Rush exhibited negligence that contributed to the deaths of the four other passengers. It further states that had he survived, Rush may have faced criminal liability and a potential Department of Justice investigation. However, no blame was placed on the US Coast Guard or other authorities.

Primary cause: OceanGate failed to follow engineering protocols

The just-released US Coast Guard Marine Board of Investigation (MBI)'s report states that OceanGate’s failure to adhere to established engineering practices was the primary causal factor in the implosion.

Eight key contributing issues were listed, including:

• Inadequate engineering and testing
  OceanGate failed to apply essential engineering principles during the design and testing of Titan, leading to an unsafe hull structure for deep-sea operations.
• Lack of hull life analysis
  No proper analysis was conducted to determine the expected fatigue life or durability of Titan's carbon-fibre hull.
• Over-reliance on real-time monitoring
  OceanGate depended too heavily on a real-time hull monitoring system without properly analysing the data it produced.
• Continued use after damage
  Despite incidents that damaged the hull and other components, OceanGate continued using Titan without thorough inspections or assessments.
• Flawed hull construction
  Deficiencies in the carbon-fibre hull’s design and manufacturing – such as winding, curing and glueing – compromised its structural integrity.
• Neglect of post-incident investigations
  OceanGate failed to conduct proper investigations after Titan experienced previous mishaps that could have affected its safety.
• Toxic workplace culture
  A hostile environment – where raising safety concerns could lead to termination – discouraged staff from reporting issues.
• Lack of preventative maintenance
  Titan’s hull was not properly maintained or protected during its offseason, weakening its condition before the 2023 expedition.

USCG report released: Key findings published after two-year investigation

The US Coast Guard Marine Board of Investigation (MBI) has released its long-awaited 335-page Report of Investigation (ROI) into the 2023 Titan submersible disaster. The report concludes that the catastrophic implosion was caused by a loss of structural integrity in the sub’s carbon-fibre hull, resulting in the instantaneous death of all five people on board.

Netflix's Titan: The OceanGate Disaster reveals ignored safety warnings and a culture of silence

A comprehensive new Netflix documentary, Titan: The OceanGate Disaster, reveals the many steps OceanGate head Stockton Rush skipped in his single-minded mission to get the Titan project off the ground. The documentary, which spoke to key insiders who worked with Rush, reveals that to avoid scrutiny, the Titan submersible was not flagged by any classification society and rubber-stamped as safe, something which US Coast Guard investigator Capt Jason Neubauer “had not seen in 26 years of investigations.”

Rob McCallum from expedition specialist EYOS, who had initially been talking to OceanGate about coming on board as a partner, left the project early on when Rush told him he “saw no need for third-party oversight.” “He had every contact in the submersible industry telling him not to do this, but once you start going down the path of doing it entirely yourself, you realise you’ve taken the wrong turn right back at the beginning, particularly for Stockton, and you have to admit you are wrong, that’s a big pill to swallow.”

One of Rush’s selling points was that he had the world’s leading submersible expert Paul-Henri Nargeolet behind the project. “PH’s involvement is always going to be a mystery to us,” said McCallum. “He was told a number of different times that he was lending his credentials to something that had a clear and obvious flaw to it.”

The documentary revealed how paying passengers were given the title of “mission specialist,” which McCallum said was used by OceanGate to work around US legislation, providing legal protection in case something went wrong. It also revealed that a scale model of the second hull – built after cracks were discovered in the first – failed its depth tests.

Nevertheless, construction of the second full-scale hull proceeded, ultimately resulting in its catastrophic implosion. After the penultimate Dive 80, when cracks were heard, Titan was brought back and instead of being taken in for investigation, was left on the dock in freezing conditions, a fact that experts warned could further weaken the structure of the carbon fibre.

The documentary also looked in depth at Rush’s absolute conviction that carbon fibre would work, along with his bullish leadership style and fiery temper meant staff were too afraid to speak out and air safety concerns. “People knew that if you challenged the boss on some of these issues, then there was a possibility you would be gone,” said Neubauer. This was seen in the later resignations of OceanGate’s director of marine operations David Lochridge and director of engineering Tony Nissen. As people resigned, teams became more streamlined. According to McCallum, by the end, OceanGate had become a small, insular group whose unwavering belief in their mission had taken on an almost cult-like intensity.

Tony Nissen concluded by saying that the work culture was ultimately the downfall of OceanGate. “It’s not simply the idea that they didn’t follow a set of regulations … It's culture that causes this to happen. It is culture that killed the people.”

BBC2’s Titan documentary Implosion: “Everyone who stepped on board after Dive 80 was risking their life”

A first Titan hull suffered cracks through delamination (layers of carbon fibre hull unravelling) in 2019, leading Rush to rebuild a new hull “with slight modifications to the processing of the carbon fibre.”

This is just one of the findings revealed in BBC2’s documentary Implosion which aired last night (Tuesday 27 May).

The cracks happened on Test Dive 47 in the Bahamas as the team was trying to reach a two-mile depth, the depth of the Titanic wreck. Submersible expert Carl Stanley, who worked with Rush, was onboard and heard a sound like a gunshot. “The sounds were continuing, so at some point, collectively, we came to a decision of, well, that's good enough. I'm sure we were within a few percentage points of implosion.” Stanley told the Marine Board of Investigation that he warned Rush over a series of emails but was ignored.

The documentary also revealed that loud cracks were heard on the replacement hull during Dive 80, which took place on 15 July 2022. Acoustic data obtained by the Coast Guard Marine Board of Investigation (MBI) showed that Oceangate had recorded the loud cracks, suggesting that the carbon fibre was again delaminating. “When they heard this loud bang, there should have been all stop, do not continue, investigate further to make sure that the carbon fibre hull was still safe for people to operate in,” said MBI technical advisor Lieutenant Commander Katie Williams. “Everyone who stepped on board after Dive 80 was risking their life.”

Titan continued with three more dives over the following week to complete the season. One year later, on Dive 88, Titan imploded, killing all five passengers on board.

The documentary also spoke to businessman and passenger Alfred Hagan, who paid $200,000 to join the expedition. Hagan was onboard when the sub's titanium nose fell off as the submersible was being pulled up after an aborted dive. Mr Rush had taken the decision that only four of a possible 18 bolts needed to be used to fix the titanium nose to the carbon fibre hull before a dive.

In response to allegations made in the film, Oceangate said they were cooperating with the official investigations, and it would be inappropriate to comment before the conclusion.

Footage reveals moment Titan sub imploded

BBC’s soon-to-air documentary Implosion: The Titanic Sub Disaster offers unprecedented footage from Titan’s support ship, capturing the moment the sub imploded during its fatal June 2023 dive.

The video, recently obtained by the US Coast Guard (USCG), has been presented as evidence to the USCG Marine Board of Investigation, which has spent the last two years examining the sub’s catastrophic failure. The footage shows Wendy Rush, Stockton’s wife, reacting to the implosion sound – a “door slam” noise – that the USCG confirmed as the moment Titan failed.

The film also reveals that Titan’s carbon fibre hull began to fail a year earlier due to delamination, a critical weakness that experts warned made the vessel unsafe. Despite these warnings, the sub continued to operate until its tragic implosion.

The USCG Marine Board of Investigation has spent two years examining the incident, with a final report expected later this year.

Implosion: The Titanic Sub Disaster airs on BBC Two at 9pm on Tuesday 27 May and will be available on BBC iPlayer.

Titan hearing: US Coast Guard's public hearing into submersible disaster concludes

The US Coast Guard's public hearing into the loss of the Titan submersible disaster began on 16 September at the Charleston County Council Building, South Carolina, and lasted two weeks, concluding on 27 September.

The hearing aimed to uncover the facts surrounding the incident and develop recommendations to prevent similar tragedies. A statement released by the US Coast Guard explained: "The hearing will examine all aspects of the loss of the Titan, including pre-accident historical events, regulatory compliance, crewmember duties and qualifications, mechanical and structural systems, emergency response and the submersible industry."

As the Titan hearing has drawn to a close, the board will publish its final public report, which could include a definitive cause of the accident, bring forth new regulations on deep-sea diving and even criminal charges.

The US Coast Guard Marine Board of Investigation chair Mr. Jason Neubauer said the investigation would continue for months, although MBI reports have been known to take much longer to be published. Rule changes will take years more. In the meantime, the National Transportation Safety Board (NTSB) is working on its own report, as are the governments of Canada and France.

11 former employees of American tourism and expeditions company OceanGate testified before the Coast Guard Marine Board of Investigation (MBI), in addition to a range of industry specialists.

Notable figures included engineer David Lochridge, who alleges he was fired from OceanGate in 2018 for raising safety concerns about quality control, as well as Triton Submarines' co-founder Patrick Lahey, who shared his first public comments on the Titan submarine disaster on a special episode of the Big BOAT Interview. He said the submersible was an "experimental monstrosity that should never have carried people".

BOAT provided daily coverage and updates on the court hearing as it unfolded.

Day nine of the US Coast Guard's public hearing: Ex-OceanGate employee flags early red flags as Coast Guard confirms no safety changes post-Titan

• Former member of the US Coast Guard Matthew McCoy, who worked for OceanGate between April - September 2017, testified. He told the hearing OceanGate had broken ties with the applied physics lab at the University of Washington, calling this the "first alarm bell" when no explanation was given. The second alarm bell was that “Boeing wasn’t going to be doing the carbon fibre” for the first sub hull.
• McCoy said he raised concerns about the lack of certificate of inspection for the first Titan sub in 2017 with OceanGate CEO Stockton Rush and OceanGate’s director of quality assurance Scott Griffith. McCoy testified that Rush said he would "buy a congressman" to make problems go away. He handed in his notice the following day.
• Captain Jamie Frederick, the US Coast Guard employee who oversaw the rescue mission of the Titan submersible, gave evidence next. He recalled the moment the Coast Guard received a call about "overdue" Titan. The initial challenges in the search were the distance off-shore, the lack of presence from the Canadian Coast Guard initially, and the 3,000 metre ROV (remotely operated vehicle) depth.
• Scott Talbot, a search and rescue specialist with the Coast Guard, was last to testify. He confirmed that the US Coast Guard has not updated safety protocols since the Titan submersible tragedy.

Day eight of the US Coast Guard's public hearing: OceanGate declined Coast Guard inspection as new map shows Titan’s proximity to Titanic wreck

• The hearing kicked off with testimony from NASA engineer Justin Jackson, before hearing from John Winters, a marine inspector with the Coast Guard, and Lieutenant Commander Jonathan Duffett of the Coast Guard Office of Commercial Vessel Compliance.
• Winters said that former OceanGate CEO Stockton Rush "did express on multiple occasions that regulations were stifling his innovation process" . He said OceanGate did not ask the Coast Guard to inspect Titan and that he only spoke to Rush about the sub in passing when he mentioned wanting to take a vessel to the Titanic wreckage.
• Maps were also released revealing how close the Titan sub was to the Titanic wreck site before disaster hit. While the sub's last known position before the implosion was 1,600ft away from the bow of the Titanic, its debris was found much closer to the bow at 300m away, Coast Guard officials said.

Day seven of the US Coast Guard's public hearing: New Titan sub wreckage images reveal carbon fibre hull damage linked to repeated dives

• Dr. Don Kramer, National Transportation Safety Board engineer, William Kohnen, Hydrospace Group Inc. (also the chairman of the Manned Underwater Vehicles Committee) and Bart Kemper, principal engineer of Kemper Engineering, then took to the stand.
• Dr. Kramer, an engineer with the National Transportation Safety Board, said the Titan sub’s carbon fibre hull showed signs of flaws, while Kohnen testified that the vessel’s carbon fibre hull was weakened on repeat dives to the Titanic wreck.

Day six of the US Coast Guard's public hearing: Former employee dismissed after raising safety concerns, close friend recalls CEO warning about hull noises

• The MBI released remotely operated vehicle footage of the Titan submersible’s salvage from June 26, 2023, which was recovered and transported to a secure facility for detailed analysis.
• Amber Bay, former OceanGate director of administration, testified first on Tuesday. She said when a former employee raised safety concerns, Rush asked Bay to release the employee from her contract because "she had acted erratically, unprofessionally".
• Karl Stanley, from the Roatan Institute of Deepsea Exploration, and a close friend of Rush, testified next. In April 2019, Stanley went on board the Titan sub on an expedition in the Bahamas. He said: "He told us to be prepared for noises. He had recently done the solo dive on his own, and basically just said, ‘this is going to make noise’ and ‘brace yourselves'."

• Stanley said there were "a lot of red flags" during the dive, including the fact he did not tow out deeper which showed Rush did not have "a lot of faith" in the sub. He also noted how Rush did not drive the sub, adding: "He didn’t do any of the driving. I believe I was the first one to drive, but he basically insisted it was his idea. Nobody asked to drive. I think that was his kind of sick way of [saying], if we had imploded, we were a little bit in control of our own destiny."
• Stanley also testified hearing cracking noises on the submersible and that it was so frequent he could "localise where it was coming from."

• He continued to say,  in retrospect, he would not have gone on the dive in 2019. Asked if he was aware there was a lightning strike in the vicinity of the sub in the Bahamas just before the 2019 dive, he responded: "The first time I heard of a lightning strike was reading about it. There’s a lot of things that, if I had known, I wouldn’t have gone," Stanley said.
• Following the dive, Stanley emailed Stockton Rush about concerns about a hull defect, which were read at the hearing. "I think that hull has a defect near that flange, that will only get worse. The only question in my mind is will it fail catastrophically or not," Stanley told Rush via e-mail.
• Stanley also addressed how he felt he was indirectly told not to discuss his concerns. The email continued: "The fact that you indirectly told me not to speak about the noises I heard on the dive, to me, says a lot. As you know, my subs have had many issues and incidents over the years, at no point did I find it necessary to tell anyone not to speak of what I saw or heard."

Day five of the US Coast Guard's public hearing: CEO Stockton Rush insists “no one dying under my watch” before implosion, engineer warns outdoor storage may have degraded Titan’s hull

• Guillermo Söhnlein founded OceanGate with Rush in 2009. He left the company in 2013 when it became clear it wanted to transition to engineering. In his closing remarks, Söhnlein said: "This was not supposed to happen." He continued: "Five people should not have lost their lives."
• A transcript of a meeting between Rush and Lochridge, the former director of marine operations for OceanGate who raised concerns with Rush about safety, was also made public ahead of the US Coast Guard’s hearing. In the transcript, Rush said: "I understand this kind of risk, and I'm going into [this] with eyes open and think this is one of the safest things I will ever do."
• Rush told Lochridge: "So I have no desire to die, and I'm not going to die. What may easily happen is we will fail. We will get down there and we will find that the acoustic monitoring has, you know, [failed] after 10 hours or gives false – too many false positives or that the thing is noisy or the dome is creaking because we're going to be measuring that or it starts to craze. I can come up with 50 reasons why we have to call it off and we fail as a company. I'm not dying. No one [is] dying under my watch, period."
• Roy Thomas, a senior principal engineer with the American Bureau of Shipping (ABS), testified next. He explained the challenges of carbon fibre materials and said it is not an approved material for classification.
• Thomas also testified that the ABS recommends sub owners store vessels in controlled environments. The US Coast Guard stated that OceanGate stored the submersible outside during winter. Thomas said: "To expose it to the elements could possibly lead to degradation of the materials."
• Former OceanGate engineering director Phil Brooks then claimed no maintenance was done on the Titan hull between 2022 and 2023.

Day four of the US Coast Guard's public hearing: Titan called an experimental vessel with incomplete carbon fibre hull and “amateurish” execution, experts raise safety concerns

• Fred Hagen testified and explained he paid OceanGate to be a mission specialist on the company’s first trip to the Titanic wreckage.
• Similar to Dr Ross' testimony earlier in the week, he said he heard a "loud bang" come from the vessel during a dive in 2022. The crew discussed what may have happened to Titan and were concerned the “hull had cracked”. Asked if he had concerns about the noise, Hagen said: "You're in a submersible and there's a loud bang. You would have to be brain-dead to not be somewhat concerned".
• When asked if he would've felt safe going down to depth again after the bang, he said: "Anyone that felt safe going to depths in Titan was delusional. It was an experimental vessel, it was clear that it was dangerous. Anyone that wanted to go was either delusional if they thought it wasn't dangerous, or they were embracing the sort of risk."
• Hagen continued: "It's like jumping out of an aeroplane. You don't do it because it's safe. You do it because it's an adrenaline rush and, yeah, I would've gone back down again. We weren't going in search of safety. We were going down in search of adventure and exploration."
• Dave Dyer, an engineer from the University of Washington, gave evidence next. The university partnered with OceanGate to produce the Titan submersible and he initially "felt like there was a very good chance it could be successful - the design looked like it was heading down the right path".
• Dyer claimed the “carbon fibre hull design was not complete", explaining failures that happened while testing the Titan around 2017. He continued: “They had not figured out what had happened on those failures from my perspective, and I had not seen an effort to modify or change the design.”
• Dyer explained the relationship between the university and OceanGate began to break down following disagreements about the company's approach to engineering and testing. The two ceased work together in 2017.
• Patrick Lahey, CEO of Triton Submarines, was next to testify. Lahey is planning the first voyage to the Titanic wreckage since the Titan tragedy and testified about the importance of certification. Lahey said he voiced concerns to Stockton Rush (OceanGate's CEO) about Titan’s prior glass dome design when he saw the submersible in 2019 and stressed the importance of certifying the vessel. Lahey said Rush deemed classification “an impediment to innovation".  Lahey said he’d never sell one without classification.
• Lahey was asked about the several other issues he'd previously mentioned when he was looking at a prototype by OceanGate in the Bahamas in 2019. He quoted the execution of the parts, including the bolt that screws into the hull and the fact that it didn't have lift points. He said: "It just seemed to me that it hadn't been particularly well thought out or executed. I saw elements where they were crimping cables to hold on weights, it just looked amateurish in its execution. I left that visit thinking, 'Well, that's a relief, I don't think that will ever take people on any significant dives'. Obviously, I underestimated their tenacity."
• When asked if he believed if someone could learn to pilot a submersible in a day, Lahey replied: "You might be able to make it go up and down, backwards and forwards. But that doesn't make you a pilot. To be a pilot you need to understand what to do if something goes wrong, how to fix things when they break, how to diagnose faults, and that isn't something you can accomplish in a day, no."

Day three of the US Coast Guard's public hearing: new wreckage footage released; mission specialist testifies and scientific director recalls “loud bang” days before implosion

• Remotely operated vehicle footage of the Titan submersible’s aft dome, aft ring, hull remnants and carbon fibre debris on the seafloor was released by the Coast Guard Marine Board of Investigation.
• Reneta Rojas testified and explained she was a "mission specialist" for OceanGate. When asked what this entailed, she said it was a volunteer position and was "someone who gets involved in the operation". Describing her background – where she studied and pursued a career in banking "instead of oceanography" – she explained she had been a scuba diver from age 12 and was "obsessed" with the Titanic, especially when she "found out non-scientists could go".
• Asked about her role on the day of the incident, Rojas explains she was the "platform assistant". When asked about the protocol and rescue, she explained the submersible was due to resurface at 6.00pm. When this didn't happen, the plan was to try to regain communication, carry out search patterns and, finally, call the coastguard. Asked if this was an "adequate plan", she says: "That's above my pay grade. I'm a technical scuba diver, not a submersible."
• Rojas was asked if any OceanGate employees had brought up safety concerns and she mentioned one employee, Tim, who "wouldn't get in the sub".
• In an emotional statement, Rojas said: "I knew what I was doing was very risky, but I never at any point felt unsafe." She added: “What we’ve all gone through is still very raw. Nothing is ever going to bring our friends back."
• Rojas testified that on the day of the implosion, she was part of the dome-closing team. When asked if anything was different for that voyage, she replied: "Not that I remember." She continued to say her role as mission specialist was just to "supervise", that she was not "involved in any critical decision-making" and that it was not her job to inspect the bolts.
• Former OceanGate scientific director Dr Steven Ross was next up. He recounted being "concerned" by a "loud bang" heard during a test dive.
• Dr Ross also told the board about a platform issue the experimental submersible experienced in June 2023, just days before the Titan submersible imploded. The malfunction up-ended the submersible at a 45-degree angle as it attempted to return to the floating platform, causing passengers to "tumble about". Rush was the pilot.
• Dr Ross explained that, following this, there was no debrief and that he was not aware of any further inspection afterwards.

Day two of the US Coast Guard's public hearing: OceanGate whistleblower cites “no experience,” rushed timeline and “deficiencies in the product itself”

• Lochridge, OceanGate's former operations director, testified and explained how Rush (the CEO) and the former engineering director of OceanGate Tony Nissen, removed the University of Washington Applied Physics Lab (APL) from the project to design the Titan vessel in-house. Lochridge went on to say he had "no confidence whatsoever" in the way Titan was being built at the time.
• Lochridge explained why his concerns were dismissed: "Cost-cutting. Bad engineering decisions. I'd say that's the two main things. The desire to get to the Titanic as quickly as they could to start making profit." He continued: "There was a big push to get this done, and a lot of steps along the way were missed and it was pretty evident, not just to myself [but also to other] experienced submersible pilots".
• Lochridge continued: "We all voiced concerns about what was happening in terms of the engineering of Titan and even more so when the components started arriving at the facility in 2017."

• He added: "There was no experience across the board within that organisation. [...] It was all smoke and mirrors – all the social media you see about all these past expeditions. They always had issues with their expeditions. I didn't know this at the time until I [moved across to OceanGate], speaking to contractors that had been on the previous jobs."
• In terms of the products used to make the submersible, Lochridge said: "Everything that came in had anomalies or deficiencies in the product itself". He also said that all the parts were repurposed from the original vessel, with the exception of the carbon fibre hull, which was down to cost: "I wasn't there for that, but I know firsthand that everything was reused. I am sure that will all come up as part of the investigation."

• Lochridge explained how, after he was let go from OceanGate for raising concerns, he informed the Occupational Safety and Health Administration (OSHA). He and his wife were then served a settlement and release agreement from OceanGate's lawyers. Lochridge countersued OceanGate in federal court so as to allow information relating to his claims to be in the public domain as a matter of "public safety". In November 2018, he dropped the claim.
• Lochridge also stated OceanGate wasn't willing to pay for pilot certification, including medical certifications for submersible pilots at OceanGate. He said the tragedy was “inevitable” as safety standards were ignored.

• He also provided an account of the time Rush crashed another submersible prior to the Titan sub disaster. Rush attempted to pilot the vessel to the Andrea Doria shipwreck, located off the Massachusetts coast, and reportedly threw the vessel’s controls at Lochridge in a rage when a passenger asked that someone else pilot the submersible. Lochridge stated Rush got into difficulty when he manoeuvred the craft too close to the wreck and would not cede control until the tearful passenger yelled at him.
• Lochridge's testimony was accompanied by video footage released by the Coast Guard, which showed the remains of Titan’s tail cone. This acted as conclusive evidence of the catastrophic loss of the submersible Titan and the death of all five members aboard. In the foreground, a piece of carbon fibre can be seen beside the tail cone.

Day one of the US Coast Guard's public hearing: Former OceanGate staff reveal “100 per cent” pressure to launch Titan despite safety concerns

• Former OceanGate employees Tony Nissen, Bonnie Carl, and Tym Catterson testified. Nissen explained there was "100 per cent" pressure to get Titan into the water. Meanwhile, Carl testified that Lochridge had deemed Titan as “unsafe.” According to an animated re-creation of the incident, the last words heard from the crew to the mothership were “all good here”.

Family of victim killed in Titan submersible disaster sues OceanGate for $50M

The family of French diver Paul-Henri Nargeolet, one of the passengers who died in the fatal Titan disaster, filed a wrongful death lawsuit seeking more than $50,000,000 against OceanGate (August 2024).

Accusing the submarine operator of gross negligence, the lawsuit claimed the waiver and release "failed to disclose many key, relevant risk factors, [...] regarding the design and operation of Titan or the materials used in its construction." In particular, it mentioned the submarine's carbon fibre hull, which was reportedly "not properly tested for integrity".

OceanGate has so far declined to comment on the lawsuit, which was filed in King County, Washington.

Listen: Did Titan have warnings from experts?

Speaking on a special episode of the Big BOAT Interview alongside Rob McCallum, co-founder of EYOS Expeditions, Triton Submarines' co-founder Patrick Lahey recalls pleading with his long-time friend and Titanic expert Paul-Henri Nargeolet, who was killed in the incident, not to dive with OceanGate. "I tried to do everything I could to discourage him from going out there. I know many people that knew him did the same thing."

McCallum also discusses his now well-publicised email exchange with OceanGate CEO Stockton Rush, who also died on the dive, warning him that he was courting disaster by taking the uncertified Titan submersible to such extreme depths.

"He was completely dismissive," McCallum says. "The minute I found out it was going to be an unclassed vehicle, that's when the alarm bells rang. But perhaps the biggest red flag of all was when a senior member of the OceanGate team wrote a report laying out the 26 or 27 things wrong with the sub and suggested solutions to those problems and he was silenced."

McCallum also relates the final time he met Rush, at a dinner, when, "I told him in no uncertain terms that he was doing the wrong thing".

Lahey also met Rush, and toured the OceanGate submersible while it was being tested in the Bahamas. "There were glaring defects. I made this list of things for them to address. But when I looked at it, I thought I didn't have to worry too much as there was no way it was ever going to see the light of day."

Both Lahey and McCallum underline the point that to prevent similar incidents, all submersibles should be subject to third-party certification.

"It's essential," says Lahey. "If people insist on [accreditation] you can be assured that the craft that you're getting in has been reviewed independently by a group of professionals and according to a set of rules, it will be safe. If you look at the track record of certified craft, it is without peer – 50-plus years of absolute safety."

The Big BOAT Interview Special: understanding the OceanGate submersible tragedy

You can listen to the full interview with Lahey and McCallum on the BOAT Briefing podcast. A new episode is released every week, and you can listen via Apple Podcasts and Spotify. Don't forget to subscribe so you never miss an episode of the superyacht industry's biggest podcast.

Has there been an inquiry into the Titan submersible disaster?

An investigation into the incident was launched by the US Coast Guard in June 2023, convening a Marine Board of Investigation (MBI) to determine “whether there is need for new laws or regulations, or amendment or repeal of existing laws or regulations, to prevent the recurrence of the casualty.”

• On 28 June 2023, debris and evidence recovered from the seafloor were handed over to the Coast Guard
• Later, marine safety engineers with the MBI conducted a follow-up salvage mission, recovering additional presumed human remains from within the Titan debris, which were analysed by US medical professionals (4 October 2023)
• In early 2024, a transcript purporting to capture communication between the submersible and mothership was declared fake by Captain Jason D. Neubauer, chairman of the MBI, who said: “I’m confident it’s a false transcript. It was made up.”