MOKPO, South Korea — The captain of a doomed ferry delayed evacuation for half an hour after a South Korean transportation official ordered preparations to abandon ship, raising more questions about whether quick action could have saved scores of passengers still missing Friday and feared dead, according to a transcript of the ship-to-shore exchange and interviews with a crewmember.

The order by an unidentified official at the Jeju Vessel Traffic Services Center to put on lifejackets and prepare for evacuation came just five minutes after a Wednesday morning distress call by the Sewol ferry. The ferry, which was bound for Jeju island, replied that “it’s hard for people to move.”

The confirmed death toll from Wednesday’s sinking off southern South Korea was 25, the coast guard said. But 48 hours after the sinking, the number was expected to rise sharply with about 270 people missing, many of them high school students on a class trip. Officials said there were 179 survivors.

CAPTAIN SAYS HE’S SORRY

The captain hasn’t spoken publicly about his decision-making, and officials aren’t talking about their investigation. But the new details about communication between the bridge and transportation officials follow a revelation by a crewmember in an interview that the captain’s eventual evacuation order came at least half an hour after the distress signal.

Meanwhile, divers worked in shifts to try to get into the sunken vessel, where most of the missing passengers are thought to be, but strong currents would not allow them to enter. The divers planned to pump oxygen into the ship to help any survivors.

A private company has sent a robot to help aid rescue operations, but Kim said the robot is still a prototype and hasn’t yet been used.

Out of 29 crewmembers, 20 people, including the captain, Lee Joon-seok, 68, survived, the coast guard said.

The captain made a brief, videotaped appearance, although his face was hidden by a gray hoodie. “I am really sorry and deeply ashamed,” Lee said. “I don’t know what to say.”

Kim Soo-hyun, a senior coast guard official, said officials were investigating whether the captain got on one of the first rescue boats.

Kim Han-sik, president of Chonghaejin Marine Co., the ship’s owner, also apologized separately, bowing deeply and saying through his tears, “I committed a sin punishable by death. … I am at a loss for words. I am sorry. I am sorry.”

The 480-foot Sewol had left Incheon on the northwestern coast of South Korea on Tuesday for the overnight journey to the southern resort island of Jeju. There were 475 people aboard, including 325 students from Danwon High School in Ansan, which is near Seoul.

VESSEL BEGAN LISTING

It was three hours from its destination Wednesday morning when it began to list for an unknown reason.

Oh Yong-seok, a helmsman on the ferry with 10 years of shipping experience, said that when the crew gathered on the bridge and sent a distress call, the ship was already listing more than 5 degrees, the critical angle at which a vessel can be brought back to even keel.

The first instructions from the captain were for passengers to put on life jackets and stay where they were, Oh said.

Video that was shot by a survivor, truck driver Kim Dong-soo, shows the vessel listing severely with people in life jackets clinging to the side of the ship to keep from sliding. The initial announcement for passengers to stay in their quarters can be heard.

A third mate reported that the ship could not be righted, and the captain ordered another attempt, which also failed, Oh said. A crew member then tried to reach a lifeboat but fell because the vessel was tilting, prompting the first mate to suggest to the captain that he order an evacuation, Oh said.

About 30 minutes after passengers were told to stay in place, the captain finally gave the order to evacuate, Oh said, adding that he wasn’t sure that in the confusion and chaos on the bridge if the order was relayed to the passengers. Several survivors said they never heard any evacuation order.

By then, it was impossible for crew members to move to passengers’ rooms to help them because the ship was tilted at an impossibly acute angle, he said. The delay in evacuation also likely prevented lifeboats from being deployed.

“We couldn’t even move one step. The slope was too big,” said Oh, who escaped with about a dozen others, including the captain.

Passenger Koo Bon-hee said many people were trapped inside by windows that were too hard to break. He wanted to escape earlier but didn’t because of the announcement to stay put.

“The rescue wasn’t done well. We were wearing life jackets. We had time,” the 36-year-old Koo said from a hospital bed in Mokpo where he was treated for minor injuries. “If people had jumped into the water … they could have been rescued. But we were told not to go out.”