The clock is ticking on the desperate search for a submersible vessel that dove to view the wreck of the RMS Titanic, as officials approximated the search area to be “larger than the state of Connecticut.”

The U.S. Coast Guard held a news conference Tuesday and said the craft had about 40 hours of oxygen left. However, a former FBI dive team leader told Fox News not to count on that estimation.

“The first thing I would do is caution people to use — to not put a lot of faith in the 40 hours left,” Bobby Chacon said on America Reports. “Those calculations are estimates bad on normal working conditions. If a person is injured, or they’re stressed, or panicking, their air consumption increases, so, that number of available hours goes down. So, if people are injured on that vessel, if they’re panicked that vessel, they are going to use more oxygen or more air more quickly. So, those are only estimates. And they are best-case estimates in normal operating conditions, which we don’t have here.”

The craft, operated by OceanGate Expedition, headquartered in Everett, WA,  left St. John’s, Newfoundland, at 4 a.m. on Saturday, but lost communication with the mothership approximately an hour and 45 minutes into the 12,500-foot dive.

“In the phase of the dive that lost contact, which is where we think the malfunction occurred, was on the descent, which is the increasing pressure,” Chacon said. “So, you have to start assuming that whatever went wrong was due to the increasing pressure. Once you hit bottom, the pressure remains constant until you start ascending. They were in the descent phase, so you can make certain assumptions about what caused the malfunction. In this case, I would assume that the increase in pressure — so there was some kind of compromising the integrity of that hull at some point that allowed the pressure to cause a malfunction, and that’s the worst case scenario.”

A crew of five people, including the pilot, are on board the vessel. According to The New York Times, the passengers who paid $250,000 a piece are British billionaire Hamish Harding, 59; Pakistani-born billionaire Shahzada Dawood, 48, and his son, 19-year-old son Suleman Dawood; and French maritime expert Paul-Henry Nargeolet, 77. It’s believed that OceanGate’s CEO Stockton Rush, 61, was piloting the submersible.

Watch the video via Fox News above.

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