Titanic submersible likely hit by 'trinity of disasters'

The OceanGate Expeditions' submersible vessel that went missing during a dive for exploration of the Titanic shipwreck could have suffered from either a hull breach, a fire, or an entanglement, known as the "trinity of disasters" that all expeditions try to avoid.

Joe MacInnis, a renowned Canadian explorer and surgeon who has visited the Titanic site four times, said the first of those scenarios is "not survivable", Bloomberg reported.

On the other hand, the second and third outcomes are manageable. The crew trains its passengers to deal with fire emergencies, and while it is difficult, all decent submarines are equipped with firefighting potential.

MacInnis — who is also a close friend of one of the divers aboard the missing submersible — knows what it was like to be imprisoned by a deadly passenger ship and survive in the process, as he had experienced a similar situation over 30 years ago when he was trapped inside a Russian Mir submersible that was caught in wires after landing on the floor of the Titanic's pilot house floor.

The expedition was, fortunately, able to send a second submarine underwater to evaluate the issue and assist the chief pilot in navigating the necessary navigation to wiggle free.

According to MacInnis, the ability to self-rescue — whether with a second sub or a remotely-operated vehicle that can be rapidly flown to the spot — is critical on such excursions. France has sent the Atalante, a research vessel outfitted with an underwater robot, to locate the missing craft.

"A hull failure is catastrophic. There is this kind of implosion, and it's terrible," the 86-year-old MacInnis said in an interview.

The 21-foot (6.5-meter) submersible, named Titan, was carrying three fee-paying passengers when it vanished on Sunday, including British billionaire Hamish Harding, Pakistani tycoon Shahzada Dawood and his son Suleman, while it is also carrying OceanGate Expeditions founder Stockton Rush and French maritime expert Paul-Henry Nargeolet.

MacInnis said three of the crew members are likely new to deep-sea diving. "They would have been on adrenaline before the dive. And in a high-stress moment they will be red-lined." Nargeolet, meanwhile, is MacInnis' close personal friend.

"PH is the best person you could be in a sub with. He is very, very calm under extreme stress. If they're still alive, he will be a terrific calming influence on the others," the Canadian explorer said, speaking about his friend.

If the Titan had simply lost radio communication, the standard strategy for it would be to surface immediately, according to MacInnis, whose work on the 1992 IMAX film Titanica inspired American filmmaker James Cameron to produce the Hollywood blockbuster Titanic.

The octogenarian explorer said he was "stricken" to find out about the missing submersible. "Getting lost in the depths is a primal fear. My heart goes out to the guys in the subs 0 and the team on the surface trying to solve the problem," he added.