Eight foreigners and five Indonesians were rescued Monday two days after their tourist boat sank during a storm in the archipelago, with one man describing how they huddled in a lifeboat and floated in life jackets to survive.
The rescue brought to 23 the number of people saved since the vessel carrying 25 sank Saturday as it headed from Lombok island to Komodo island, famed as the home of the Komodo dragon, the world's biggest lizard.
Among them were 18 foreign tourists, from New Zealand, Britain, Spain, the Netherlands, Germany, France and Italy. Some of the group rescued Sunday had to swim hours to the closest island, Sangeang, even though there was a volcano erupting on it at the time.
Two foreigners remain missing. Those rescued Monday were found in the early hours some 60 miles (100 kilometres) off the coast of Sumbawa island, close to Sangeang, search official Budiawan said.
A Dutchman in the group said that they were in the water for about 40 hours, taking turns to spend time in the lifeboat -- which seated seven people -- and floating in the water in the life jackets.
"So we had this system, and in the beginning it was not easy ... but later on the system went on, and we changed and changed," Jan van Ommen told AFP from the town of Sape on Sumbawa, where the group was taken after being rescued.
He said the boat hit a coral reef after setting off from Lombok on Thursday but the crew insisted there was no problem and the voyage continued.
However on Friday night, the vessel was hit by a storm and started to take on water.
"The crew came out shouting 'very dangerous situation'," he said, adding that they saw water leaking into the boat. As the boat slowly sank and broke apart, some decided to swim to Sangeang. Van Ommen and six others crammed into a life boat, while six others wearing life jackets swam alongside, he said.
"At the end of the second day they found us," he said, speaking from a local health centre where some of the survivors were being treated.
'Very lucky' rescue
The foreigners rescued Monday were from the Netherlands, Italy and Germany, while the Indonesians were four boat crew members and a tour guide, said national disaster agency spokesman Sutopo Purwo Nugroho.
Budiawan, who like many Indonesians goes by one name and is head of the search and rescue agency on Lombok, said the search operation was ongoing, and involved the military and police.
French survivor Bertrand Homassel told AFP Sunday how and he and a group of others had to swim for six hours to reach Sangeang.
"Six people were in the lifeboat. The others climbed onto the roof of the boat, which had not completely sunk," he said, speaking from a hotel in Bima, a city on Sumbawa where those rescued Sunday were taken.
"We waited until midday on Saturday. We were five kilometres (three miles) from the coast -- there were many big waves separating us from the coast.
"People started to panic... Everyone took the decision to swim to the closest island, five kilometres away, where there was an erupting volcano."
He said they arrived in Sangeang as the sun was setting, but found it deserted. They spent Saturday night there, surviving by drinking their own urine and eating leaves.
On Sunday, they attracted the attention of a passing boat by waving their life jackets, and were rescued and taken to Bima, he said.
"I was really very lucky," Homassel added.
Komodo island is one of several islands that make up the Komodo National Park, a protected area.
Its eponymous lizards can grow up to three metres (10 feet) long and have a venomous bite.
Indonesia relies heavily on boats to connect its more than 17,000 islands, but has a poor maritime safety record. However boat sinkings involving foreign tourists are rare.