The missing crew may only have a few hours of oxygen left, based on estimates of the Titan submersible‘s initial supply.

CityNews Nigeria reports that the search is being expanded – aircraft and ships, as well as remotely operated vehicles, are combing around 10,000 sq miles of ocean.

More noises have been heard in the search but it remains unclear what they are, the US Coast Guard says.

Capt Jamie Frederick has vowed it remains a search and rescue operation, adding: “We have to remain optimistic and hopeful”.

Contact with the sub – which has five people on board – was lost on Sunday as it made a descent to the Titanic wreck.

Meanwhile, CityNews Nigeria learnt that a remotely operated vehicle (ROV) from UK company Magellan is currently being loaded onto a C17 plane at Jersey Airport.

Their sub – called Juliet – recently scanned the Titanic wreck, producing a 3D view of the entire ship.

Once it leaves, it will take about 48 hours to get to the site – which is beyond the timeline given for air for the passengers.

It will be able to dive the full depth of the site, and the team has a detailed knowledge of the deep sea area having been there recently.

The sub has been ready to leave since earlier in the week but has been held up by permissions.

Expert says ‘catastrophic implosion unlikely’…

An expert who helped design the Deepsea Challenger submersible used by director James Cameron to view the Mariana Trench (the deepest in the world) said he believes the missing Titan sub has run out of power or is suffering from partial flooding in the pressure hull.

“To me, it sounds like the sub’s pressure hull is intact, but it’s demobilised from power,” deep-sea engineer Ron Allum told The Guardian.

“Sound travels particularly well underwater. A catastrophic implosion could be heard for thousands of miles and could be recorded,” he explained, suggesting a pressure hull implosion was unlikely.

However, he did explain that while the sub may have dropped weights to try to resurface, any flooding would keep it below the water.

“If the pressure hull is flooded, you’re now talking about the dry mass of a vessel. You could be lifting a very heavy weight,” Allum said.

“If it were intact, an ROV [remotely operated vehicle] could attach to it and it could at least bring it up to shallower water where they could get a stronger lift cable to it to lift it out of the water … that ascent may take an hour or two.

“The ROV may have to work around the wreckage … it may take a few hours to release the sub from the seafloor.”

Ocean Gate/Alamy