Rescuers plucked a woman from choppy waters Monday, some 25 hours after she jumped from a crowded ferry that sank in a storm off Indonesia's Sumatra island. At least 29 people drowned and 20 others were missing.

A total of 255 survivors have been pulled from the sea since Sunday when the Dumai Express 10 was hit by towering waves and sank about 90 minutes into an inter-island trip from Batam to Dumai in Riau, a province off Sumatra island in western Indonesia. A second ferry ran aground nearby, but all its passengers were said to be safe.

The rescued woman in her 30s was spotted by fishermen and she was in stable condition in a hospital, said Lt. Col. Edwin, a navy officer. Like many Indonesians he only uses one name.

"Fishermen saw her floating with a life jacket on the rough sea in the rain ... She is very tough," said Edwin.

Fishing boats, police patrols, navy warships and a helicopter were still searching for 20 people reported missing, Edwin said.

"The bad weather and 4-meter (13-foot) high waves are still hampering the search and rescue," he said. "We will keep looking."

Indonesian ferry accidents have killed hundreds of people in recent years. Boats are often overcrowded, and safety regulations are poorly enforced. The vast country spans more than 17,000 islands, and boats are a popular and relatively cheap form of transportation.

The stricken ferry went down about 30 minutes after huge waves damaged its bow and water started seeping in, according to a report from the ship's captain, said Edwin.

A survivor, who only gave his name as Riki, said he escaped from the ship by breaking a window and was rescued by fishermen, the official news agency Antara reported.

"It was too fast ... and the ship crew did not tell us about the situation at all," he said. "We only managed to get out after I broke the glass window on the right side. That was the only way because there were many people jostling for the doors."

He said he saw some passengers jump into the sea without life jackets. Passing boats picked up scores of people took them to nearby islands for medical treatment.

High waves hampered the rescue operation, which had recovered 29 bodies by Sunday night, including two children, said Rustam Pakaya, the head of the Health Ministry's crisis center.

Police and navy officials said the ferry manifest listed 228 passengers, including 15 children, and in addition, there were 13 crew, but the number of people accounted for already has surpassed that.

Manifests are generally unreliable because tickets are sold onboard to passengers who are never registered.

Indonesia has suffered several major ferry accidents in recent years.

In December 2006, a crowded ferry broke apart and sank in the Java Sea during a violent storm, killing more than 400 people.