Five crew on missing sub 'have 40 hours of air left'

US Coast Guard officials said last night that the crew of the submersible Titan, which went missing in the north Atlantic during a dive to the wreck of the Titanic, had about 40 hours of breathable air remaining, if they were still alive.

- Richard Luscombe Edward Helmore

Capt Jamie Frederick also told reporters at a media briefing that a sea and air search that had begun on Sunday night for the vessel and five men onboard, and which has so far covered 7,600 sq miles of a remote area of the north Atlantic, had "not yielded any results".

Rescue teams were racing against time to locate the 6.7-metre (22ft) vessel, which had a 96-hour supply of oxygen when contact was lost on Sunday, one hour and 45 minutes into its descent to the wreck site 3,800 metres beneath the ocean's surface, about 370 miles off the coast of Newfoundland.

"We know from the data that we were using as a starting point [their available air] was 96 hours.

We know at this point we're approximately about 40, 41 hours [in]," Frederick said.

Aircraft from the US Coast Guard, US navy and Canadian military were scouring the surface by sight and radar, he added, and were able to drop sonar buoys to monitor under water earlier yesterday.

"Search efforts have continued through last night and today. Those search efforts have not yielded any results," he said, announcing that a "unified command" had been set up to coordinate the effort.

Private companies had offered vessels with deep ocean capabilities, he said: "This is a complex search effort, which requires multiple agencies with subject matter expertise and specialised equipment." Yesterday morning, military authorities said the search was expanding under the surface, using sonar and other hi-tech equipment, enhancing operations that had continued through the night.