Image Showing How Deep Titanic Sub Had To Travel Goes Viral—'Mind-Boggling'

One Twitter user has shown the incredible depth at which a lost submersible with five passengers could be in the ocean.

The submersible vessel, named Titan, from the OceanGate Expeditions, went missing on Sunday, with global rescue efforts working tirelessly to find the vessel and save the lives of the people on board.

The company had been leading an expedition to see the RMS Titanic wreck site in the North Atlantic Ocean and was reported overdue on Sunday night at about 435 miles south of St. John's, Newfoundland, Canada.

The Titanic wreckage sits at around 12,500 feet below sea level—far lower than most submersibles can travel, but according to OceanGate, the Titan is only one of five submersibles in the world that can get to that depth.

Just how deep the wreckage is can be hard to fathom, but one simple graphic shows the mind-blowing depth the submersible attempted to travel.

Twitter user Jay Meriweather shared a graphic that compared the different sea depths to real life landmarks and the limits of ocean life.

"This [is] HOW DEEP that submarine had to go in order to get to the Titanic. Mind-boggling how far down they are," Meriweather wrote alongside the image. The tweet has been viewed over 1.3 million times.

An inverted version of New York City's Empire State building would sit just a little over 1,000 feet below the sea's surface and gives a sense of the scale of the rescue operation needed.

Other astonishing facts in the graph first published by USA Today show the maximum depth a giant squid can swim to— almost 3,000 feet—while a sperm whale can't dive deeper than 4,000 feet.

Given that the Titanic wreckage is thousands of feet below that, it explains why rescuers are so concerned about the passengers on board.

At the depth it was traveling to, the sea exerts around 400 bar of pressure while one bar is experienced at around sea level.

The U.S. Coast Guard estimated that the air supply on the missing Titan sub is likely to have run out or to have nearly done so, which has made the search ever-more pressing.

As well as the astonishing depth the sub could have reached, the search area is also very vast and was described as "two times the size of Connecticut and the subsurface search is up to 2-and-a-half miles deep," according to U.S. Coast Guard Captain Jamie Frederick, who updated the media on Wednesday.

"This is a search-and-rescue mission, 100 percent...We are smack dab in the middle of search-and-rescue and we'll continue to [use] every available asset that we have in an effort to find the Titan and the crew members," he said.

The five confirmed passengers include Stockton Rush, the CEO of OceanGate; French submersible pilot Paul-Henry Nargeolet; and billionaire British explorer Hamish Harding.

The other two passengers had their identities confirmed by their families as Pakistani businessman Shahzada Dawood and his son Suleman Dawood.

Tickets for an expedition to see the Titanic cost $250,000.

The Titanic was the world's largest ship before its shipwreck on April 15, 1912. It sank during its maiden voyage after hitting an iceberg between Southampton, England, and New York City.

Of the 2,200 passengers and crew on board, more than 1,500 died in the accident.

Its wreckage was discovered in 1985 and is believed to be 435 miles south of St John's, Newfoundland.