Rescue divers retrieved the bodies of another some 20 passengers from the wreck of the ferry Sewol on Thursday, bringing the confirmed death toll to over 180.
Currents off the southwest coast, which are among the most dangerous in Korea, slowed down enough for divers to operate in relatively safe conditions, but they are about to speed up again, hampering operations.
A total of 726 Navy and civilian divers and other rescue workers were involved in search operations on Thursday, assisted by 261 boats and 35 aircraft. Divers retrieved 34 bodies on Tuesday and 38 on Wednesday.
The families of the victims, who had been nervously watching the search operations from the shore, were dismayed at the slow pace. Some protested on Thursday afternoon to the taskforce handling the operations and pleaded with them to speed up the search.
But divers said they face extremely difficult conditions due to poor visibility and various obstacles blocking the passages of the sunken ship.
One coast guard said, "The stern of the vessel, where most of the students [from Danwon High School south of Seoul] are believed to have gathered, has a complex layout and a narrow entrance that make it very difficult, but we're trying our best."