Several survivors also told the AP that they never heard any evacuation order.
The loss of that precious time may have deprived many passengers of the opportunity to escape as the Sewol sank Wednesday, not far from the southern city of Mokpo.
Twenty people, including a female crew member, at least five students and two teachers, were confirmed dead by coast guard officials Thursday night. But the toll was expected to jump amid fears that more than 270 missing passengers — many high school students — were dead. Coast guard officials put the number of survivors Thursday at 179.
Video obtained by AP that was shot by a survivor, truck driver Kim Dong-soo, shows the vessel listing severely as people in life jackets cling to the side of the ship to keep from sliding. A loudspeaker announcement can be heard telling passengers to stay in their quarters.
The increasingly anxious search for the missing was hampered all day Thursday by strong, dangerous currents, rain and bad visibility. Officials said divers would continue trying overnight to enter the ship, hoping for gentler currents.
There were 475 people aboard, including 325 students on a school trip to the tourist island of Jeju in the south of the country. The ferry had traveled overnight from Incheon on the northwestern coast of South Korea and was three hours short of its destination when it began to list. The cause is not yet known.
The 146-meter (480-foot) Sewol now sits — with just part of its keel visible — in waters off Mokpo, about 470 kilometers (290 miles) from Seoul.
Oh, a helmsman on the ferry with 10 years' 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 the ship can be brought back to even keel.
At about that time, 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 tripped because the vessel was tilting, prompting the first mate to suggest to the captain that everyone should evacuate, Oh said.
The captain agreed and ordered an evacuation, but Oh said that amid the confusion and chaos on the bridge he does not recall the message being conveyed on the public address system.
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.
At a briefing, Kim Soo-hyun, a senior coast guard official, told reporters that officials were investigating whether the captain got on the first rescue boat, but didn't elaborate.
Passenger Koo Bon-hee, 36, 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 that said passengers should stay put.
"The rescue wasn't done well. We were wearing life jackets. We had time," Koo, who was on a business trip to Jeju with a co-worker, 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."