Mauger said the “combined command” was made up of some with expertise from the US Coast Guard, US Navy, Canadian Coast Guard, Canadian Armed Forces, private sector and the Woods Hole Oceanographic Institution.

He also said that the equipment required for the search effort is currently under the sea.

“We have two rove submarines that are capable of operating on the ocean floor and are now operating on the ocean floor,” he said.

He said: “Both have the ability to take pictures with a camera, use sonar, and have transparent arms capable of attaching instruments, attaching a rescue line and moving any obstacles in the way, and most importantly, they are now at the bottom of the ocean, which is the equipment we need.”

“World-class Integrated Command experts are advising us,” he added.

Getting this equipment on site, he said, was a “very complex endeavor.”

“When we started as a unified command, there was no plan for it, no equipment that had been established before, and we had to start from scratch and gather the best available equipment as quickly as possible.”

But the search for the missing submarine with five people aboard could last only a few hours, experts say, on the fifth day of an intense international search across the vast Atlantic seaboard surrounding the Titanic.

Titan, a small submersible operated by the US company Oceangate Expedition, began its descent to the seabed at 8am local time on Sunday, but lost contact with the support ship at the end of its two-hour dive to reach the wreckage. It is a century old.

After launch, enough air was charged for 96 hours, according to the company.

It may have run out of oxygen tanks sometime Thursday morning. Whether the submarine’s occupants are still strong and calm, and if Titan is intact, experts say the exact timing depends on several factors.

Rescue crews and friends and relatives of the five Titan passengers received hope when the U.S. Coast Guard said Wednesday that a Canadian search plane using sonar buoys on Monday and Tuesday detected sounds coming from under the sea.

But the Coast Guard’s remote-controlled underwater search vehicles aimed at the noise detection point yielded no results, and officials said the sounds could not have come from the Titan.

“When you’re in the middle of a search and rescue operation, you always have hope,” Coast Guard Capt. Jamie Frederick said Wednesday, adding that the noise analysis was inconclusive.

Atlante, a French research vessel equipped with a robotic diving vehicle capable of reaching below the wreckage of the Titanic, which lies about 12,500 feet (3,810 meters) above the surface, has begun moving to the area.

The French robot, called the Vector 6000, has remote-controlled arms to help free a trapped vehicle or attach it to a ship to transport it.

The US Navy is deploying a special rescue system designed to lift large underwater objects.

In 1912 the Titanic sank on its maiden voyage and then hit an iceberg, killing more than 1,500 people, 1,450 km east of Cape Cod, Massachusetts, 640 km south of Saint John, Newfoundland.

The Titan took its captain and four others on board for a trip to the wreck of the deep-sea ship, a tourist adventure that Ocean Gate Expeditions charges $250,000 per person.

Among the passengers were British billionaire and adventurer Hamish Harding, 58, and Pakistani-born tycoon Shahjata Dawood, 48, and his 19-year-old son Sulaiman, both British citizens.

French oceanographer and Titanic expert Major Paul-Henri Narcolet, 77, and Stockton Rush, founder and CEO of Ocean Gate Expeditions, were also said to be on board the submarine. Rush married the daughter of two descendants of Titanic victims.

“We’re waiting impatiently, we can’t sleep,” said Matthew Johan, one of Henry’s relatives.

Sean Leet, president of a company that jointly owns the support vessel Polar Prince, said Wednesday that all protocols had been followed, but declined to say how the connection was interrupted.

“There’s still life support on the submarine, and we’ll be hopeful until the end,” Light added.

Questions about the Titan’s safety were raised in 2018 during a submarine industry experts’ seminar, and in a lawsuit filed by Oceangate’s former head of naval operations, they were resolved later that year.

Even if crews find Titan, recovering it will present major challenges in terms of transportation and shipping.

If the submarine returns to the surface, it will be difficult to find at sea and will be sealed from the outside so that those inside cannot get out unaided.

And if the submarine Titan were at the bottom of the ocean, rescue teams would have to deal with great pressures and total darkness at that depth. Titanic expert Tim Mauldin says an undersea rescue is nearly impossible.

“The wreck of the Titanic is divided into two parts, surrounded by a cloud of debris – and finding the submarine is not easy,” said Jean Carey, an engineer who worked at the French research firm Evremer.