A New Zealand scientist was one of the key figures of the Oceangate expedition of the doomed sub Titan, the Herald has learned.

Dr Bridget Buxton, a marine archaeologist who worked alongside Oceangate CEO Stockton Rush and travelled to the Titanic wreck multiple times, previously praised the “revolutionary construction” of the submersible that claimed five lives.

Buxton, a Victoria University graduate and Fulbright scholar, is based at the University of Rhode Island and appeared in promotional material for the Oceangate describing those who paid top dollar for a trip to the wreck site as “citizen scientists”.

“A citizen scientist is also involved in the science. They are doing jobs that are essential to the scientific research, not just busy work” she said in the short promotional video which repeatedly touted the safety of the expedition, alongside a sweeping soundtrack and Hollywood voiceover.

Buxton with Oceangate CEO Stockton Rush onboard the Titan. Photo / Oceangate

Buxton offered an insight on life onboard the Titan in 2021, telling the Providence Journal: “I can tell you as an archaeologist there’s a world of difference in being right on site in a submersible with amazing 360º vision and movement compared to dealing with the limitations of an ROV (remotely operated vehicle).

She said that five people could be onboard, “provided one of them’s willing to train to be a sub pilot (and the controls are similar to a PlayStation console, so a lot of people already have those skills). And yes, you can talk to each other normally.”

“Most of the time we’re also listening to music.”

The carbon-fibre construction of the Titan has come in for criticism since the craft’s catastrophic implosion, with experienced deep-sea adventurer James Cameron saying it had “no strength” at the depths it went to.

“It’s not what it’s designed for,” he told the New York Times.

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OceanGate’s director of marine operations, David Lochridge, wrote a report about January 2018 saying Titan needed to be tested more and there were “potential dangers to passengers ... as the submersible reached extreme depths”.

In March 2018, industry leaders, deep-sea explorers and oceanographers wrote to Rush saying OceanGate’s “experimental” approach and lack of certifications could result in “catastrophic” consequences.

But in 2021, Buxton was full of praise for the sub.

She said its “revolutionary construction of carbon fibre and titanium” made it “more accessible and affordable to scientists and people in developing countries.”

“The submersible can be operated behind any ship,” she said in a news release quoted by the Providence Journal.

“In addition to deep ocean exploration, it can also be used in shallow and coastal areas. This technology makes it much more affordable to do oceanographic research.”

After news broke that her colleagues and their clients had not survived the voyage, Buxton paid a simple tribute, sharing a photo of herself with the Oceangate team at sea.

Dr Bridget Buxton with the Oceangate team.

The Titanic exploration submersible’s resting place is right next to the shipwreck punters had paid big money to visit, and it is believed those on board died “in milliseconds” after a “catastrophic implosion”.

The five men on Titan - Hamish Harding, Stockton Rush, Paul-Henri Nargeolet, Shahzada Dawood and his son, 19-year-old Suleman Dawood - “would have had no idea what was happening” when they died, one expert has said.

Suleman Dawood’s aunt, Azmeh Dawood, told NBC her nephew was “terrified” ahead of the trip: “[He] wasn’t very up for it. I am thinking of [him] in there, just perhaps gasping for breath.”

A search and rescue effort led by the United States Coast Guard and involving aircraft, ships and underwater equipment from Canada and France ended overnight Thursday, NZ time, when debris was found near the Titanic.

It has also been revealed by an anonymous senior US Navy official an acoustic system used to detect submarines recorded an “anomaly” on Sunday - the day Titan went missing - which was likely the sound of the fatal implosion.

This photo combo shows from left, Shahzada Dawood, Suleman Dawood, Paul-Henri Nargeolet, Stockton Rush, and Hamish Harding are facing critical danger aboard a small submersible that went missing in the Atlantic Ocean. The missing submersible Titan imploded near the wreckage of the Titanic, killing all five people on board, the U.S. Coast Guard announced Thursday, June 22, 2023. (AP Photo/File)

Azmeh Dawood said the death of her brother, Shahzada, and nephew, Suleman, had been “crippling”.

“I feel like I’ve been caught in a really bad film, with a countdown, but you didn’t know what you’re counting down to… I personally have found it kind of difficult to breathe thinking of them,” Dawood told NBC.

She told NBC her brother was “absolutely obsessed” with the Titanic.

“He was my baby brother… I held him up when he was born,” she said.

Shahzada Dawood, 48, was a British-Pakistani billionaire and philanthropist from one of Pakistan’s wealthiest families. He also worked for SETI, a research organisation that searches for extra-terrestrial life.

His son, Suleman, was a “big fan of science fiction literature and learning new things,” according to a family statement. He liked Rubik’s cubes and volleyball.

His aunt said he was reluctant to go on the trip but wanted to please his father.

Shahzada Dawood, 48, a board member of the Prince's Trust charity, and his son Sulaiman Dawood, 19, are two of the five people onboard the missing OceanGate Titanic submersible.

Another victim, Paul-Henri Nargeolet, 77, was nicknamed Mr Titanic as he had visited the wreckage of the Titanic 35 times. Nargeolet was a former French Navy diver.

Hamish Harding, 58, was a British billionaire who held three Guinness World Records. He once visited space with Jeff Bezos’ Blue Origin and also visited the South Pole with Buzz Aldrin, the second man on the moon after Neil Armstrong.

Rush, 61, was an experienced engineer who had worked on experimental aircraft and other submersibles.

Earlier hope for the crew after reports banging noises had been detected, which have now been dismissed as coming from something other than Titan, was dependent on the sub’s oxygen supply lasting.

The oxygen was expected to run out on Thursday night, before the US Coast Guard revealed in a press conference it had told crew members’ families they had died.