A race against time is underway, led by American and Canadian authorities, to locate the Titan submarine, which disappeared during a tourist expedition around the wreck of the Titanic. Time is running out as the five people aboard the stricken submersible – a pilot and four passengers – now have around 40 hours of oxygen, at most, according to the US Coast Guard. The Titan, a submersible operated by OceanGate Expeditions, began its descent to the wreck of the Titanic on Sunday. Authorities lost contact with the craft an hour and 45 minutes later. Canadian and American authorities have mobilized several planes and ships to the search area. The Titanic wreck lies at a depth of 3,800 meters in the North Atlantic Ocean, approximately 700 kilometers south of St. John’s in Newfoundland. At a press conference in Boston, US Coast Guard Captain Jamie Frederick admitted the search had yet to yield results. “This is a very complex search operation,” he said. “We have agreed to coordinate the search, but we do not have all the necessary equipment on site to conduct it,” he added. Authorities do not know if the submarine is still submerged or if it has come to the surface. “We have worked through the night with a broad group of partners to deploy all search capabilities both on the surface and now deep in the area,” U.S. Coast Guard Rear Admiral John Mauger said on Tuesday. . So far, about 13,000 square kilometers have been raked, he said. Searches for the submarine are made extremely difficult due to its small size, measuring just 6.5 meters in length.