Rescue efforts for the five passengers aboard the Titan submarine continue with only a few hours left before the available oxygen inside the vessel runs out. Authorities maintain their prospects of finding the crew alive, Coast Guard spokesman Captain Jamie Frederick said Wednesday. "We are optimistic and hopeful," he stated. But they are also aware that it is a complex mission due to the depth at which the submersible may be sitting.

The U.S. and Canadian Coast Guard deployed the necessary resources to carry out this operation. These include the offshore fisheries science vessel CCGS John Cabot, the Canadian anchor-handling vessel Motor Vessel Horizon Arctic, the research vessel L'Atalante, the coastal defense vessel HMCS Glace Bay and the remotely operated vehicle for handling Magellan ROV underwater drones. The search is also being conducted from the air to facilitate visual contact by radar.

On Wednesday, a Canadian plane on the submarine rescue mission detected some sounds at 30-minute intervals coming from the area of the disappearance. Recall that the rescue operation was established in a search perimeter similar to the size of the Connecticut area. The U.S. Department of Defense (DOD) has also joined the mission. "We are assisting in search operations," DOD deputy press secretary Sabrina Singh reported.

The trail of the tourist submarine Titan was lost last Sunday while on an expedition in the Atlantic Ocean, it was carrying several passengers down to view the wreckage of the Titanic, which sank about 370 miles off Newfoundland in the early morning hours of April 15, 1912. On board the submersible were Pakistani tycoon Shahzada Dawood and his son Suleman; Action Aviation company president Hamish Harding; French adventurer Paul-Henry Nargeolet; and Ocean Gate CEO Stockton Rush.