Search and rescue teams in Indonesia are keeping up a search for about 400 people missing after a ferry sank in a storm off the coast of Java.
Naval boats cannot reach survivors trapped in rough seas
Aircraft have been dropping food and water to those adrift in lifeboats who cannot be picked up in bad weather.
People have been known to live for days in warm tropical waters, but there are fears survivors could die from dehydration unless rescued soon.
About 180 of the 600 people on board have been found alive so far.
Rescue workers flying over the area have spotted many more clinging to life rafts on Sunday and Monday.
However the search operation is being hampered by continued stormy weather.
The ferry, the Senopati Nusantara, sank early on Saturday off Mandalika island, about 300 km (190 miles) north-east of the capital, Jakarta.
Some survivors have been picked up by local fishermen
It was travelling from the port of Kumai, Borneo, to Semarang in Java.
The cause of the accident is unclear.
Survivors have described panic as the Senopati began to sink and passengers scrambled to climb aboard lifeboats, many of which broke apart leaving people drifting in the water.
One said there were not enough life jackets and that passengers had fought over them as the boat capsized.
"I was going upstairs to try to help my daughter, but the ship suddenly broke up and I was thrown out. I lost her," he told AP news agency.
Ships and ferries are a cheap and popular means of transport between the 17,000 islands that make up Indonesia.
Correspondents say safety standards are not always enforced and vessels frequently carry more passengers than they are meant to.
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