The Titanic wreckage – which the Titan submersible was en route to see before it disappeared – sits over 2 miles below the ocean surface

• The Titan submersible was en route to see the Titanic, which sits at a depth of 2.4 miles (12,672 feet).
• That's the equivalent of about 35 football fields stacked end-to-end.

People have long been drawn to the mystery and intrigue of the RMS Titanic, the British passenger liner that sunk in April 1912 on its maiden voyage.

However, most haven't had the chance to see the wreckage up close themselves.

That is what the 5-person crew of the Titan submersible was on its way to do before it disappeared on Sunday an hour and 45 minutes into its dive.

How deep is the Titanic wreckage?

The journey to the Titanic wreckage – which sits about 2.4 miles, or 12,672 feet, below the surface – usually takes about two hours, according to USA Today.

For reference, the wreck rests at a depth that's about 35 football fields (end zones included) stacked on top of each other end-to-end.

The Titan is designed to reach depths of 13,123 feet, according to OceanGate, the company behind the sub.

While discussing ventures to the ocean's depths on the Titan, Dan Scoville, the company's Director of Engineering and Operations, described it as an experience rarer than walking on the moon.

"More people have walked on the moon than have been to the Titanic," Scoville said in 2020. "So it's pretty rare for anyone to be at those kinds of depths in the ocean. It's a really exciting opportunity."

As a mass search and rescue operation is underway, US Coast Guard officials have said the vessel, if it's still intact, only has enough oxygen to last the pilot and 4 passengers until Thursday afternoon. Other variables may change that estimate, like how quickly the passengers use oxygen.

OceanGate said in a tweeted statement on Monday that they are "mobilizing all options to bring the crew back safely."