By the time the order came, however, he said it had become impossible to help many of the passengers - although the captain and a dozen crew members survived.
The confirmed death toll from Wednesday's sinking of the Sawol off southern South Korea was 25, the coast guard said. But the number was expected to rise with about 270 people missing, many of them high school students on a class trip. Officials said there were 179 survivors.
Divers worked in shifts to try to get into the sunken vessel, but strong currents would not allow them to enter, said coast guard spokesman Kim Jae-in. The divers planned to pump oxygen into the ship to help any survivors, but first they had to get inside, he added.
The water temperature in the area was about 12 degrees Celsius (54 degrees Fahrenheit), cold enough to cause signs of hypothermia after about 90 minutes of exposure.
Kim said three vessels with cranes are being brought in to help with the rescue and to salvage the ferry, which sank not far from the southern city of Mokpo and now sits with just part of its keel visible.
The captain of the Sawol, identified by broadcaster YTN and the Yonhap news agency as 68-year-old Lee Joon-seok, was questioned by the coast guard and 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 146-meter (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,
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 obtained by The Associated Press 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 also told the AP that 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.
It is not clear if the captain's actions violated any procedures, and he may have believed at the time that it was still possible to control the vessel, which would have made the order to evacuate unnecessary.
Passenger Koo Bon-hee told the AP that 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."
In Mokpo, relatives of the dead students wailed and sobbed as ambulances began carrying the recovered bodies back to Ansan. The families, who spent a mostly sleepless night at the hospital, followed the ambulances in their cars.
The family of one of the dead, 24-year-old teacher Choi Hye-jung, described her as a woman who loved to boast about her students who came to her office to give her hugs.
"She was very active and wanted to be a good leader," her father, Choi Jae-kyu, 53, said at Mokpo Jung-Ang Hospital while waiting for the arrival of his daughter's body. Choi's mother, sitting on a bench at the hospital, sobbed quietly with her head on her knee.
The last major ferry disaster in South Korea was in 1993, when 292 people were killed.
Klug reported from Seoul. Associated Press writers Hyung-jin Kim in Ansan and Jung-yoon Choi in Seoul contributed to this report.