A submersible that takes tourists to the Titanic shipwreck went missing and has about 96 hours of life support onboard

• A submersible that takes tourists to see the Titanic shipwreck has gone missing.
• The Boston Coast Guard told the BBC a search was underway for the missing sub.

A search mission is underway for a submersible that takes tourists to visit the Titanic shipwreck, the US Coast Guard based in Boston told told the BBC.

The sub lost contact with its mother ship less than two hours after submerging Sunday morning, the US Coast Guard confirmed via a tweet Monday. The USCG also confirmed there are five people on board the sub.

OceanGate Expeditions told CBS News on Monday that its submersible is the subject of the search and rescue operation, and that it was "exploring and mobilizing all options to bring the crew back safely." OceanGate Expeditions did not confirm whether any crewmembers were paying tourists, according to CBS.

An OceanGate Expeditions spokesperson previously told Insider the company worked with NASA to design and engineer its deep-diving carbon fiber submersible, called the Titan.

The Titan is the only sub in OceanGate's fleet that is made to go as deep as the wreck, which sits 12,500 feet at the bottom of the Atlantic Ocean, about 370 miles off the coast of Newfoundland, Canada. The Titan can fit five people — one pilot and four crewmembers — and has 96 hours of life support on board, according to OceanGate's website.

"Our entire focus is on the crewmembers in the submersible and their families," OceanGate Expeditions said in its written statement to CBS.

"We are deeply thankful for the extensive assistance we have received from several government agencies and deep sea companies in our efforts to reestablish contact with the submersible," OceanGate added.

Technically, the vessel is not a submarine, which has enough power to leave port and return under its own power, according to the National Oceanic and Atmospheric Administration (NOAA). A submersible has limited power reserves and requires a so-called "mother ship" that can launch and recover it, according to NOAA.

In this case, another vessel called Polar Prince, which is a Canadian research vessel used to transport submersibles to the Titanic shipwreck, was involved in the expedition, according to the US Coast Guard. Polar Prince lost contact with Titan about 1 hour and 45 minutes into the vessel's dive on Sunday, the US Coast Guard said.

Just last week, OceanGate Expeditions tweeted that it relies on Starlink for communication while aboard the sub, as there are no cell towers in the middle of the ocean.

Tourists can pay to board small submersibles to explore what's left of the British passenger liner that lies in two main pieces nearly two and a half miles down.

OceanGate Expeditions charges customers $250,000 for a spot on its 8-day expedition to see the world's most famous wreck.

In 2022, OceanGate Expeditions released a high-quality video of one of its Titanic tours, Insider previously reported, which was the world's first and only 8K video of the underwater wreck at the time of publishing.

The footage unearthed new details about the iconic ship that sunk in 1912, which will help archaeologists further study the rate of decay of the Titanic. The slow but sure decomposition of the wreck has been a point of research in recent years, as deep-sea currents, salt corrosion, and metal-eating bacteria whittle away the once-massive vessel.

Some scientists believe the wreck could disappear by 2030, Insider previously reported.

Insider has reached out to OceanGate and the US Coast Guard for comment.

This story is developing and will be updated.