International experts with sophisticated acoustic detection gear have joined teams scouring the sea for the wreck of an Indonesia AirAsia passenger jet.
However, bad weather is again hindering the hunt for the plane's black box flight recorders.
Strong winds and heavy seas have stopped divers from looking for the fuselage of the Airbus A320-200, which went down on Sunday en route from Indonesia's second-biggest city Surabaya to Singapore.
The Indonesian-led search for the wreck of Flight QZ8501, which had 162 people on board, is centred in the northern Java Sea, off Borneo island.
Ten bodies and pieces of the broken-up plane have been recovered, but no survivors have been found.
"With the increasing amount of evidence and data, it's very likely we're getting closer to the fuselage of the AirAsia aircraft, based on what has been detected by sea vessels," Supriadi, operations director of the Indonesian search and rescue agency, said.
Two ships carrying hydrophones, or underwater listening devices, left the southern Borneo port of Pangkalan Bun today, Indonesian officials said.
Aboard one vessel were experts from France's BEA accident investigation agency, which attends the crashes of all Airbus planes.
However, officials were unsure if the weather would allow the sensitive hydrophones to be deployed.
It is the first crash suffered by the AirAsia group since the budget operator began flying in 2002.
Investigators are working on a theory that the plane stalled as it climbed steeply to avoid a storm about 40 minutes into a flight that should have lasted two hours.
Officials earlier said it may take up to a week to find the black boxes, which investigators hope will unravel the sequence of events in the cockpit during the doomed jet's final minutes.
Even in bad weather, however, the search for the AirAsia plane is less technically challenging than the two-year search for an Air France jet that crashed into deep Atlantic waters in 2009, or the fruitless hunt for Malaysia Airlines Flight MH370 that disappeared last year.
Given Flight QZ8501 crashed in shallow seas, experts say finding the boxes should not be difficult if its locator beacons, with a range of 2,000 to 3,000 metres and a battery life of around 30 days, are working.
Ten bodies have been recovered from waters near the suspected crash site, search and rescue agency head Soelistyo said, along with debris such as a suitcase, an emergency slide and a life jacket.
The bodies are being taken in numbered coffins to Surabaya, where relatives of the victims, most of whom were Indonesian, have gathered.
Authorities have been collecting DNA from relatives to help identify the bodies.
The plane was travelling at 32,000 ft (9,753 metres) and had asked to climb to 38,000 ft to avoid bad weather just before contact was lost.
When air traffic controllers granted permission to fly at 34,000 ft a few minutes later, they received no response.
A source close to the investigation said radar data appeared to show the aircraft made an "unbelievably" steep climb before it crashed, possibly pushing it beyond the A320's limits.