Banging sounds heard in the vicinity of a <a href="https://www.thenationalnews.com/world/us-news/2023/06/21/missing-titanic-submarine-banging/" target="_blank">submersible that went missing </a>while visiting the wreck of the Titanic are “inconclusive” and further attempts to detect additional noises have been unsuccessful, the US Coast Guard said on Wednesday. <b>Follow the latest news on the missing </b><a href="https://www.thenationalnews.com/world/us-news/2023/06/22/titanic-submarine-missing-live/"><b>Titanic</b></a><b> sub here</b> Noises were heard by a Canadian P-3 Orion surveillance aircraft on Tuesday and again on Wednesday morning, Capt Jamie Frederick of the US Coast Guard said at a press conference in Boston. Additional scans by two Remotely Operated underwater Vehicles (ROVs) listening for sounds in the area had yielded “negative results”, he added. Capt Frederick said the surface search is now approximately two times the size of the US state of Connecticut, which measures about 13,000 square kilometres. “We need to have hope, but I can't tell you what the noises are … It's inconclusive,” he said. The operation to find <a href="https://www.thenationalnews.com/world/uk-news/2023/06/20/hunt-for-missing-titanic-submarine-what-we-know-so-far/" target="_blank">Titan, the deep-sea vessel</a> that had four wealthy tourists and a pilot aboard, was still being treated as a “search and rescue” rather than “recovery”. “We are smack dab in the middle of search and rescue and will continue to put every available asset that we have in an effort to find <a href="https://www.thenationalnews.com/world/2023/06/20/titanic-submarine-missing-search-titan/" target="_blank">the Titan and the crew members</a>,” Capt Frederick said. <a href="https://www.thenationalnews.com/world/us-news/2023/06/21/titanic-submarine-missing-air/" target="_blank">Titan</a> was projected to have about 96 hours of oxygen on board when it went missing on Sunday, meaning it could run out of air by Thursday morning. When asked if he is hopeful of finding the submersible inside the time frame, Rear Admiral John Mauger told BBC News there is a “possibility” as the search and rescue operation continues to take priority. “We understand from the emergency life-support system that there is a possibility and so we are prosecuting this to the fullest of our ability, bringing as many assets as we can to bear on this and different assets so we are able to collect different information and be prepared for contingencies as well,” he said. He added that the US Navy has mobilised a submerged object recovery system, while the Canadian Armed Forces have mobilised a recompression chamber with medical support. “We’re preparing for contingencies while remaining laser-focused on the search for the submersible and those people.” <a href="https://www.thenationalnews.com/world/2023/06/20/how-could-the-five-passengers-on-the-titanic-submarine-be-rescued/" target="_blank">Titan</a> lost communication with tour operators on Sunday while about 700km south of St John’s, Newfoundland, during a voyage to <a href="https://www.thenationalnews.com/world/uk-news/2023/06/21/titanic-the-worlds-enduring-fascination-with-the-famous-shipwreck/" target="_blank">the Titanic shipwreck</a> off the coast of Canada. Carl Hartsfield of the Woods Hole Oceanographic Institution told reporters that it was difficult to discern between human-made sounds and natural sounds, including sea animals. “The noises have been described as banging noises,” he said. “But again, [analysts] have to put the whole picture together in context and they have to eliminate potential man-made sources other than <a href="https://www.thenationalnews.com/world/uk-news/2023/06/20/titanic-submarine-passenger-communication-failed-on-my-mission-too/" target="_blank">the Titan</a>. “There are a lot of vessels in the area and they each make noise. So all of that has to be eliminated.” Rob Larter of the British Antarctic Survey told <i>The National </i>that some sounds can travel for hundreds of kilometres under water. “If you have a big industry seismic exploration source, you can actually hear that from hundreds of miles. If you have sensitive detection equipment you can. But I’m sure there are experts on site who understand these things,” said Mr Larter. Five surface vessels are searching for the <a href="https://www.thenationalnews.com/world/uk-news/2023/06/21/dubai-businessman-who-explored-titanic-on-missing-sub-dismisses-safety-concerns/" target="_blank">Titan</a>, with another five expected to join within 48 hours, Capt Frederick said. The mini-sub was designed to remain under water for 96 hours, giving its occupants until Thursday morning before the air supply runs out, if the craft is still intact. Experts have suggested it is possible they could survive a little longer than the initial 96 hours if they take turns sleeping and expend minimal breaths by not talking. Capt Frederick said the five people on the Titan – four tourists and the sub's pilot – have “limited rations” aboard. Those on board the submersible on a tourist expedition that costs $250,000 a person include three fee-paying passengers: British billionaire <a href="https://www.thenationalnews.com/uae/2023/06/20/titanic-submarine-hamish-harding-is-an-adventurer-who-bravely-explores-the-unknown/">Hamish Harding</a>, 58, who lives in Dubai, as well as Pakistani-born businessman Shahzada Dawood, 48, and his son Suleman, 19, who are also British citizens. Pilot Stockton Rush, chief executive of the company leading the expedition, was at the helm, with French submersible pilot Paul-Henri Nargeolet the final person on board. Col Terry Virts, a former US pilot and friend of <a href="https://www.thenationalnews.com/world/uk-news/2023/06/20/hamish-harding-titanic-submarine-stockton-rush/" target="_blank">Mr Harding</a>, described him as the “quintessential” British explorer. He added that the design of the vessel was very simple, meaning there were not many things that can break on it, and that other submarines on other missions to the <a href="https://www.thenationalnews.com/uae/2023/06/21/hamish-harding-family-put-great-faith-and-trust-in-titanic-submarine-rescue/" target="_blank">Titanic</a> have become stuck. “That’s a dangerous place to operate when you [the submersible] just have one window,” he said. “It’s not like when you are backing up your car you have your backup camera, you have your two mirrors and your rear mirror. I hope that’s the problem. “That would be the best-case scenario, because it would mean they are still alive and there would be at least a hope for rescue.” As well as an international fleet of ships and planes, an underwater robot had begun to search near <a href="https://www.thenationalnews.com/world/2023/06/20/titanic-missing-submarine/" target="_blank">the Titanic</a> site and there was a push to get salvage equipment to the scene in case the sub is found. “The first task is to find the craft, which would be no mean feat,” said David Andrews, professor of engineering design at University College London. “Even on the surface, which would be the best chance of a successful rescue, it will still be difficult to find because the craft is so small and low in the water. “If the vessel is on the bottom of the ocean, finding it will be even harder. It took [US explorer Robert] Ballard a very long time to find the relatively enormous Titanic in 1985.” But Richard Garriott de Cayeux, president of the New York-based Explorers Club, which has members on board the submarine, wrote on Twitter that “data from the field” had given the club renewed hope. “We understand that likely signs of life have been detected at the site,” he wrote. “We await hopefully good news.” In a November 2022 episode of his <i>Unsung Science </i>podcast, CBS journalist David Pogue interviewed Mr Rush ahead of a Titan expedition to the Titanic. In the podcast, Mr Rush told him: “You know, at some point, safety is just 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. “At some point, you’re going to take some risk, and it really is a risk-reward question. I think I can do this just as safely by breaking the rules.” A former employee of OceanGate raised concerns over the safety of the vessel in an engineering report in 2018. David Lochridge, OceanGate’s director of marine operations, wrote that the craft under development needed more testing and that passengers might be endangered when it reached “extreme depths”, according to a lawsuit filed that year in US District Court in Seattle. OceanGate sued Mr Lochridge that year, accusing him of breaching a non-disclosure agreement, and he filed a counterclaim alleging that he was wrongfully fired for raising questions about testing and safety. The case settled on undisclosed terms several months after it was filed. Retired Rear Admiral Chris Parry expressed bafflement over why people would use the “dodgy” Titan submersible, especially after signing away their right to sue the responsible company, stating it's “fundamentally dangerous” and accusing users of an element of “hubris”.