US ship faces challenges in hunt for Indonesia jet

MAKASSAR, Indonesia, Jan 10 (Reuters) A US navy ship that joined an undersea hunt for an Indonesian plane missing for nine days with 102 people aboard could face difficulties because of the depth of the possible wreckage, officials say.

''The (USNS) Mary Sears has a multi-signal device. It can receive a lot of signals at one time so that it can figure out the silhouette of the objects,'' said First Air Marshal Eddy Suyanto, the Makassar air base commander coordinating the search.

The search for an Adam Air Boeing 737-400 that vanished in bad weather on January 1 was chiefly focused on large metal objects detected on Monday by Indonesian ships with sonar technology in deep water north of Mamuju in west Sulawesi.

But Suyanto told Reuters the depth of the objects was around 1,000 metres (1,150 yards) to 1,500 metres. That could present problems.

Mark Jarrett, deputy director of operations for the US Naval Oceanographic Office, said the vessel conducted oceanographic surveys and can map the sea bed, but had its limits.

''In shallow water that's not too difficult to do, in less than 500 metres. Any deeper ... and it will be very difficult for our ship to identify any parts, especially if they're small,'' he told Reuters in Washington.

Officials say none of the ships involved in the operation, including two additional Indonesian navy vessels that joined the search, carry submersible vessels capable of reaching the sea bed and examining possible wreckage first hand.

SEARCHES GO ON Other air, land and sea searches meanwhile continued over, in and around Sulawesi island for the plane that vanished on its way to Manado in the north. But Suyanto said reports of wreckage sightings on land were ''negative'' yesterday.

The plane disappeared less than three days after a ferry with more than 600 aboard capsized and sank off Java.

Fourteen people were rescued this week after drifting hundreds of miles on a life raft for nine days, bringing the total number of survivors to at least 248.

Hundreds were still unaccounted for and the Senopati Nusantara ferry had yet to be found, although Tony Syaiful, spokesman for the Indonesian navy's eastern fleet, said two navy ships had been combing the Java Sea north of Central Java province for the past two days.

Their sonar had detected a number of signals but there were ''a lot of old ruins and mines from World War Two in the area.

Therefore we have to do a thorough investigation,'' he said.

The areas being searched are about 60 metres deep, allowing divers to check out significant findings, he added.

Planes and six navy vessels kept up the search for survivors and bodies from the ferry.

REUTERS AKJ KP1113