Divers looking for the wreck of an AirAsia Indonesia jet off Borneo were unable to resume full-scale operations on Thursday in poor weather and heavy seas and an air safety official said it could take a week to find the black box flight recorders.
Crews were on standby to descend to a large object detected by sonar on the ocean floor, lying just 30-50 metres (100-165 feet) deep. Rescuers believe it is the Airbus A320-200, which was carrying 162 people when it crashed on Sunday en route from the city of Surabaya to Singapore.
"I am hoping that the latest information is correct and aircraft has been found," airline boss Tony Fernandes tweeted on Thursday. "Please all hope together. This is so important."
Toos Sanitiyoso, an air safety investigator with the National Committee for Transportation Safety, said he hoped the black box flight data and voice recorders could be found within a week, suggesting there was still doubt over the plane's location.
Tweet: I am hoping that the latest information is correct and aircraft has been found. Please all hope together. This is so important.
"The main thing is to find the main area of the wreckage and then the black box," he told reporters.
None of the tell-tale black box "pings" had been detected, he said.
"There are two steps of finding the black box. One is we try to find the largest portion of the wreckage," he said.
Frogman commander Lieutenant Edi Tirkayasa said the weather was making it difficult for even professional rescue divers.
"What is most difficult is finding the location where the plane fell - checking whether the aircraft is really there," he told Reuters.
"This is very difficult even with sophisticated equipment. With weather like this, who knows. We are still hopeful and optimistic that they'll find it. They must."
Investigators are working on a theory that the plane stalled as it climbed steeply to avoid a storm about 40 minutes into the flight.
Read More Why we still can't track an airplane
So far, at least seven bodies have been recovered from waters near the suspected crash site, along with debris such a suitcase, an emergency slide and a life jacket.
The bodies are being taken in numbered coffins to Surabaya, where relatives of the victims have gathered, for identification. Authorities have been collecting DNA from relatives to help identify the bodies.
"We are asking universities to work with us - from the whole country," said Anton Castilani, executive director at Indonesia's disaster victims identification committee.
Most of those on board were Indonesians. No survivors have been found.
Relatives, many of whom collapsed in grief when they saw the first grim television pictures confirming their fears on Tuesday, held prayers at a crisis center at Surabaya airport.
"Unbelievably" steep climb
The plane was travelling at 32,000 feet (9,753 metres) and had asked to fly at 38,000 feet to avoid bad weather. When air traffic controllers granted permission for a rise to 34,000 feet a few minutes later, they received no response.
A source close to the probe into what happened said radar data appeared to show that the aircraft made an "unbelievably" steep climb before it crashed, possibly pushing it beyond the Airbus A320's limits.
"So far, the numbers taken by the radar are unbelievably high. This rate of climb is very high, too high. It appears to be beyond the performance envelope of the aircraft," he said.
The source, who declined to be identified, added that more information was needed to come to a firm conclusion.