Image source, Ifremer

Earlier on Tuesday, it was announced the French research vessel Atalante was asked to provide support in the ongoing search for the Titan submarine.

The Atalante is within 48 hours of navigation from the Titanic wreck location.

On board is the autonomous robot Victor 6000, which can dive to the depth of the wreck.

Atalante is due to reach the area where the search operation is taking place about 20:00 (00:00 GMT) on Wednesday.

Max Matza
Reporting from Everett, Washington

I've come to the city of Everett in Washington, just north of Seattle, to try to speak to OceanGate employees.

At the Port of Everett’s Craftsman District Boat Repair Yard, where the submersible company is based, nobody answered their unmarked door on Tuesday morning.

It appears as if the OceanGate sign outside has been removed and the bay windows have been papered over.

On the window is a sticker which says: "Titanic survey expedition 2019".

A worker, repairing the fiberglass hull of a boat next door, says he doesn't personally know the roughly eight OceanGate employees.

"It's usually just hi and bye," he says, adding that most of the company's boat repairs are done inside its warehouse and not in the parking lot - where other boats are being fixed today.

"It was a big deal when they left for the Titanic," says Don Downhour.

He says that's when he saw several large trucks transporting the submersible, as well as a Bayliner, which he describes as the type of ship he wouldn't want to take on the open ocean.

Another ship worker who didn't want to give his name called the situation "terrible".

I asked him if this is one of the dangers of the shipping industry and he shrugged and told me: "Don't know. I don't work with submersibles".

Image source, Getty Images

A Hercules aircraft will fly over the area where the missing submersible could be, the Pentagon has said.

Two C-130 military aircraft conducted search and rescue flights on Monday and a National Guard C-130 flight will take place on Tuesday, the Department of Defense disclosed during a briefing attended by CBS News - the BBC's US news partner.

The US Navy is also sending a salvage system to assist with the submersible, with equipment and service people arriving in Newfoundland on Tuesday night.

A Navy spokesperson said: "The navy is sending subject matter experts and a Flyaway Deep Ocean Salvage System (FADOSS), motion compensated lift system designed to provide reliable deep ocean lifting capacity for the recovery of large, bulky, and heavy undersea objects such as aircraft or small vessels."

The Titan submersible could be below the surface in ultra deepwater - the craft is capable of reaching 4,000m in depth.

Rescuers are hoping sonar equipment will help detect any activity below the surface.

US President Joe Biden has expressed his thoughts for the missing submersible's crew and family members, a White House official has said.

John Kirby, a senior official, told reporters the president is watching events closely.

He also said the US Navy, who have deep water capabilities the US Coast Guard might not have, is on standby.

"We continue to, including the president, express our thoughts to the crew on board, as well as to what is no doubt worried family members back on shore," he said.

Image source, Reuters

In addition to the search beneath the water, there are also planes circling to spot any sign of the missing sub.

The weather has improved today which makes the aerial search easier, Captain Frederick said earlier during the coast guard press conference.

There are 15 knot winds and waves up to 6ft (1.83m) - and visibility is significantly better than yesterday due to the fog easing, he said.

Nadine Yousif is in St John's, Newfoundland - where the missing crew departed from on Saturday.

Click the Play button above to hear what the locals have been telling Nadine.

Submersible operating company OceanGate has issued a brief statement confirming that CEO Stockton Rush "is aboard the submersible as a member of the crew."

The statement gave no further details.

Yesterday, the company said it had been "unable to establish communications with one of our submersible exploration vehicles".

"Every step possible is being taken to bring the five crew members back safely," the company said.

The search operation for the missing submersible is "complex" and involves both aircraft scouring the surface of the ocean and sonar buoys listening in for any activity underneath the water:

Nadine Yousif
Reporting from St John's

It is a cold, foggy and damp day here in St John’s, Newfoundland, with very limited visibility out at the harbour.

It is relatively quiet, as the search and rescue mission for the Titan submersible is being carried out 600km (372 miles) from shore.

The Polar Prince had taken off here last week, carrying with it a team of researchers and adventurers towards the wreckage of the Titanic at the bottom of the Atlantic.

Five people then went down in a submersible to explore. But we know that vessel – called Titan - lost contact with the mothership within two hours of their dive.

The well-being of those aboard has been top of mind of the locals here, who told us they have kept up with the news and are desperately hoping that the rescue mission ends with good news.

It is now day two of the search and rescue mission, but no information has been released yet on whether anything has been found.

Just a few moments ago we heard from the US Coast Guard during a press conference in Boston. Here's the top lines from its update on the search and rescue operation for the missing submersible.

• The US Coast Guard has said the missing Titanic submersible has about 40 hours of oxygen left
• The coast guard has commenced a remotely operated vehicle (ROV) dive at the last known location of the sub
• Capt Jamie Frederick said the coast guard's "heartfelt thoughts and prayers" were with the families of the five crew on board the Titan
• He said crews, including the US Coast Guard, US Navy and Canada "are working around the clock"
• The US Coast Guard says they have searched an area of 7,600 sq miles, which is bigger than the US state of Connecticut
• "These search efforts have not yielded any results," Capt Frederick said

"We are out there, we are searching," Capt Frederick says.

"If the sub is located, the experts will look at the best course of action for recovering the sub," he adds.

Capt Frederick says that it is a complex search, and it's complex for variety of reasons.

"It's 900 miles east of Cape Cod and 400 miles south of St John's. Logistically speaking it takes time and coordination and we're dealing with surface search and subsurface search."

"We will do everything in our power to effect a rescue," says Capt Frederick.

He adds if the remotely operated vehicle (ROV) finds something, experts will determine what the next steps that need to be taken are and the "best course of action".

This is a "unique operation", Capt Frederick says.

It's challenging but right now the teams are focused on doing "everything we can" to search the area and locate the sub.

He emphasizes that if the sub is located, they can't start thinking about rescue plans but they are still searching for it.

Capt Jamie Frederick reiterate it is a "very complex" search and teams are working around the clock.

He continues the coastguard will continue to give updates and their "thoughts and prayers" are with the crew and their families.

He adds their efforts will be "unwavering".

Capt Frederick has said the coast guard has commenced a remotely operated vehicle (ROV) dive at the last known location of the sub.

The current ROV deployed at the site has a camera on board, he says.

The Canadian coast guard is scheduled to arrive later this evening as well as other vessels from the US Navy. Private vessels are joining in the search too.

Capt Frederick says there is about 40 hours of breathable air left on the sub, based on the initial reports of 96 hours left.

Frederick says on Sunday the coordination and command centre in Boston connected them to inform that they lost connection with the submersible with five people on board 1 hour 45 minutes after the dive began on Sunday.

Later, a coordinated search effort began between the US coast guard and the International Guards, Polar Prince and Canada Coast Guard.

He also says that they have searched an area of 7,600 sq miles, which is bigger than the US state of Connecticut.

"These search efforts have not yielded any results," he says, adding that the operation is currently ongoing.

Capt Jamie Frederick continues offering his "heartfelt thoughts and prayers" to the families of the five people onboard the submersible.

He says "crews are working round the clock" during the rescue mission.

He adds expertise from the US Coastguard, US Navy and Canada are working together during the "complex search effort" they don't have all they need for.