A new transcript has been released of the last conversation between the crew of the South Korean ferry and officials on land, just before the boat sank.
Staff on the bridge repeatedly asked whether any boats were available to rescue passengers if they abandoned ship.
The captain was told he had to make the final call on when to evacuate.
56 bodies have now been recovered. Over 240 passengers, mostly school children, are still unaccounted for after Wednesday's disaster.
Parents and relatives waiting near the scene have expressed their anger about the pace of the rescue. Relatives had tried to march to the capital Seoul, but were stopped by police.
Coast guard official Ko Myung-Suk says things are progressing, but the conditions of the operation are difficult.
Yesterday, the ship's captain - 69 year-old Lee Joon-seok, who has been arrested - defended his actions, saying he delayed the ferry's evacuation because passengers would have been too cold in the water.