The U.S. Coast Guard said early on Wednesday that the sounds prompted diverted searches by remotely operated vehicles, noting that the endeavor had thus far “yielded negative results.”

After Canadian planes heard “underwater noises” in the search area on Wednesday, the frenzied quest to find the missing Titanic tourist submarine went on.

The U.S. Coast Guard said early on Wednesday that the sounds prompted diverted searches by remotely operated vehicles, noting that the endeavor had thus far “yielded negative results.”

According to a Coast Guard spokesman, the five individuals aboard the vessel, which went missing while on a mission to explore the Titanic ruins, had less than 40 hours of oxygen left as of Tuesday afternoon, making the search for the sub a race against time.

The people who were aboard the Titan, a missing ship, have been identified as CEO of OceanGate Expeditions Stockton Rush, Action Aviation owner and British billionaire Hamish Harding, French dive expert Paul Henry Nargeolet, and well-known Pakistani businessman Shahzada Dawood and his son Suleman.

According to previous passengers and promotional materials, the Titanic tourist submersible, which is still missing with five people aboard, is a straightforward and compact boat with a carpeted floor in place of seats and barely enough room inside for more than one person to stretch out at a time.

According to a depiction of the ship used in advertising materials, the Titan’s measurements are 22 feet by 9.2 feet by 8.3 feet. In the diagram, only one of the passengers may completely stretch their legs, and the arrangement is referred to as the “typical seating configuration.”

Previous guests have reported that the ship, which is piloted with a video game controller, lacks a conventional toilet.

According to Mike Reiss, a writer and producer who has worked on “The Simpsons” and who went on the trip last year, “it’s basically a car that you drunkenly drove into the ocean.”

The search for Titan is taking place in a hostile and inhospitable environment that is more easily comparable to space than many locations on Earth.

It’s completely dark down there. It’s quite chilly. Mud covers the uneven seabed. In an interview with NBC News Now, historian and Titanic authority Tim Maltin said, “You can’t see your hand in front of your face. “It’s kind of like being an astronaut going into space,” one person said.

However, unlike space, there is not much human presence in the world’s oceans, and there are few technologies available for search and recovery operations.

The most urgent issue in the hunt is the sub’s oxygen supply, but it is far from the only difficulty, according to Jamie Pringle, a professor of forensic geosciences at Keele University in the United Kingdom. He claimed that because the seafloor is more uneven than the land, exploring such high depths is difficult.