- Rescuers rush to find a missing submersible with five people on board.
- Crew could lose oxygen on an OceanGate Expeditions tour by Thursday afternoon.
- Here are three likely scenarios of what could have happened, according to experts.
A full-scale search and rescue operation is underway after a tourist dive boat with five people on board disappeared while on a diving mission to the Titanic shipwreck on Sunday morning.
The 23,000-pound Titan ship, owned by OceanGate Expeditions, disappeared from radar about an hour and 45 minutes after descending off the coast of Cape Cod, Massachusetts, the US Coast Guard said.
Experts estimate the crew – which includes a British billionaire and an adventurer, and a father and son from Pakistan – could run out of oxygen Thursday afternoon ET.
Underwater noise detected in the area suggests the passengers may still be alive, but time is running out for their rescue.
As rescue efforts continue, here are three scenarios that show what could have happened.
1. Titan may be bobbing around on the surface waiting to be found
That would be the “best-case scenario,” Stefan B. Williams, a professor of marine robotics at the University of Sydney whose lab uses unmanned submersibles, told Insider.
Williams said there’s a chance the device Titan used to communicate with her support ship, the Polar Prince, somehow failed and that it’s already surfaced, waiting to be found.
“That’s a possibility, but presumably the ship would have surfaced as expected at the end of the dive,” Williams said. “That seems less and less likely as time goes on.”
Ships like Titan are typically designed to either drop weights or automatically inflate floats to bring them back to the surface if something goes wrong, Williams added.
Retired Navy Rear Admiral Chris Parry told Sky News that if the ship had come to the surface it “would have been found by now”.
According to OceanGate’s website, the Titan submersible’s dive, including descent and ascent, typically takes about eight hours.
The US Coast Guard has already searched an area “about the size of Connecticut” but had no luck, CNN reported.
2. It suffered a “catastrophic implosion.”
If the submersible hasn’t surfaced again, there’s likely a “catastrophic failure,” Williams said.
The cause could be a leak or a power outage. There’s also a possibility that a small fire caused by an electrical short may have affected the vehicle’s electronic systems, which are used to navigate and control the ship, Williams said in a blog post about the submersible.
The worst case scenario would be the pressure hull breaching, resulting in a “catastrophic implosion,” Williams said.
“It would be pretty quick and the chance of survival would be slim,” he added.
3. It got tangled up in the wreckage of the Titanic
Two experts said another likely scenario is that Titan may still be intact and its passengers alive, but the ships may have become stuck near the seabed. It could have gotten caught in the wreckage of the Titanic, for example, which is about 12,500 feet underwater.
Powered by electric thrusters, the Titan can carry five people to a depth of 13,123 feet, according to the OceanGate website.
Frank Owen, a retired Royal Australian Navy officer and project manager for submarine escape and rescue, told The Guardian that the wreck on the seabed “is surrounded by debris from the disaster more than a century ago”.
“Parts of it are lying around everywhere. It’s dangerous,” he said.
That prospect is unlikely, but not impossible, Williams told Insider.
The US Coast Guard confirmed Wednesday that it picked up suspicious underwater sounds using sonobuoys, sensitive microphones attached to buoys and dropped by planes flying over the search area.
Rolling Stone previously reported that searchers on a Canadian plane detected “popping noises” at 30-minute intervals from the area where the submersible went missing.
Experts will analyze the noise to determine if it can be traced back to its source, Williams said.
“It sort of opens up the possibility that they’re still alive and gives you some hope, but obviously we’re nearing the end of their window of available air,” Williams said Wednesday morning.
“Even if they’re alive and they can locate the submarine, they still have a pretty tough task getting it back to the surface,” Williams said.
Seabed rescue is very difficult
In any case, a seabed rescue would be very difficult, Alistair Greig, a professor of marine engineering at University College London, told The Guardian.
“There are very few vessels that can go that deep, let alone divers,” he said.
Williams added that it might be difficult for the rescue team to even spot the submersible from the surface, as its sonars wouldn’t be able to spot it from the debris and uneven terrain on the seabed.
Whatever the circumstances of Titan’s disappearance, there is no doubt that those trapped inside are trying to survive in a “pretty harsh environment” when the ship is still intact and its passengers are alive, Williams said to insiders.
Without life support systems, the submarine could get very cold — the water temperature outside is near freezing, Williams said. Also, passengers typically only take a sandwich and a bottle of water onto the submersible, and there are no toilets onboard, said David Pogue, a science writer who was on the submersible last year, in an interview with NewsNation.
David Gallo, senior adviser on strategic initiatives at RMS Titanic, told CNN that falling oxygen levels and battling the cold are the top concerns for passenger safety at this time.
“The water is very deep — more than 2 miles,” Gallo said. “It’s like visiting another planet. It’s not what people think. It’s a sunless, cold environment and high pressure.”