OceanGate's expeditions to the Titanic were meant to herald a new era for deep-sea tourism, but the company's missing submersible has instead underscored the danger these journeys can bring.

The Titan, a minivan-size submersible, was carrying five people to the Titanic's watery grave when it lost contact. The vessel has enough oxygen to keep its passengers alive for about 40 more hours.

Rescue teams seeking the submersible housing five tourists that had planned to visit the wrecked Titanic said "noises" had been detected close to where the sub ended contact with its mother ship.

Retired U.S. Navy submarine Capt. David Marquet says crews would need to locate the vessel then bring it to the surface to unlatch it. He puts the odds of passengers' survival at "about 1%."

The Titanic wreck is hard to reach and harder to capture, with most images showing just a section at a time. The first full-sized digital scan offers what experts call a game-changing view.

The Titanic's rust-caked bow, an officer's cabin and a promenade window are part of the never-before-seen footage of the shipwreck site, which continues to slowly vanish 12,500 feet below the waves.

The blockbuster hit theaters on Dec. 19, 1997. Since then, fans have debated whether Jack could have survived on the makeshift raft. Now Cameron says a forensic analysis rules that out definitively.