<<Print>>

A multinational search team scanned the sea near the century-old wreck of the Titanic on Thursday, the fifth day since a tourist submersible went missing with five people aboard and with just hours to go before its air supply was expected to run out.

The minivan-sized submersible Titan, operated by U.S.-based OceanGate Expeditions, began its descent at 8 a.m. (1200 GMT) on Sunday, losing contact with its support ship near the end of what should have been a two-hour dive to the wreck.

The Titan set off with 96 hours of air, according to the company, so its oxygen tanks would likely be depleted some time on Thursday morning, although precisely when depends on factors such as whether the craft still has power and how calm those on board are, experts say, and assumes the craft is still intact.

Rescue teams and relatives and friends of the Titan's five occupants took hope when the U.S. Coast Guard said on Wednesday that Canadian search planes had recorded undersea noises using sonar buoys earlier that day and on Tuesday.

The Coast Guard said remote-controlled underwater search vehicles directed to where the noises were detected had not yielded results. Officials said the sounds might not have originated from the Titan.

"When you're in the middle of a search-and-rescue case, you always have hope," Coast Guard Captain Jamie Frederick said on Wednesday, adding analysis of the noises was inconclusive. "With respect to the noises specifically, we don't know what they are."

The French research ship Atalante, equipped with a robotic diving craft capable of reaching depths even below the Titanic wreck which lies about 12,500 feet (3,810 metres) below the surface of the North Atlantic, has been moving to the area.

The French robot, called Victor 6,000, has arms that can be remotely controlled to help free a trapped craft or hook it to a ship to haul it up. The U.S. Navy is sending a special salvage system designed to lift large undersea objects, such as small vessels.