A search is underway for Titanic touring submersible missing in the Atlantic Ocean

A submersible known for taking tourists into the deep sea to view the Titanic wreckage has gone missing in the Atlantic Ocean.

The U.S. Coast Guard in Boston told NPR that it has begun a search and rescue mission for the vessel.

The BBC reported that the submersible is owned by OceanGate, a company based in Washington state that offers underwater voyages to explore the remains of the iconic shipwreck from the seafloor.

OceanGate has not responded to a request for comment, but its website said an expedition was “currently underway,” as of June 13, according to the company’s website via the Wayback Machine.

It is unclear if people were on board at the time the vessel was declared missing, according to the BBC.

The National Oceanic and Atmospheric Administration told NPR that it is also aware of the missing submersible and is closely monitoring the situation.

The company’s deep sea tour lasts about eight days and costs $250,000 per person. About six guests can join at a time. From St. John’s in Newfoundland, Canada, explorers travel 380 miles offshore and 2.3 miles below the surface, according to the company’s website.

The company gained popularity in recent years for its expeditions to the Titanic, and most recently the group created the first-ever-full-sized digital scan of the shipwreck.

The company gained popularity in recent years for creating the first-ever-full-sized digital scan of the Titanic. Founder Stockton Rush has been pushing for deep-sea exploration to draw interest in a similar vein as privatized space travel.

Not the first time an OceanGate submersible was lost

This is not the first time an OceanGate Expeditions submersible has gone lost, according to David Pogue, a correspondent for CBS Sunday Morning.

Pogue, who traveled on an Oceangate expedition to see the Titanic last summer,recalled that the control room was unable to help the submersible locate the wrecked liner for roughly three hours due to technical difficulties.

“The difference this year is that it seems like they lost contact with the ship,” Pogue told NPR. “They can’t even reach the sub and that’s really scary.”

The deep sea is difficult to navigate because there is no GPS or radio signals underwater, according to Pogue. The submersible relies on directions sent by the control center.

“All of these submersibles have been kind of janky,” Pogue said.

He added that factors like bad weather and mechanical issues can hinder the expedition. In fact, the vessels rarely make it to the Titanic, despite the expensive price tag, according to Pogue.