Bad weather delayed recovery efforts on the sunken ferry Sewol on Thursday, lowering hopes that weak tidal currents would help along the search for more than 30 people still missing in the deadly sinking three weeks ago.

Currents were expected to weaken this week as a result of neap tides, when the difference between high and low tide is the least.

However, unfavorable weather conditions continued to create high waves that forced divers to put their operations on hold for long intervals at a time.

On Thursday morning, wind was measured at a speed of 12 to 13 meters per second, while waves reached 2.1 meters high.

Divers plan to re-enter the submerged vessel at least three times during the day when currents are weakest as well as any time weather conditions improve, officials said.

The search operations are expected to focus on the front of the third and fourth decks, inside cabins and main corridors, in addition to the back of the fourth deck. Wednesday's search was also concentrated on those areas.

The plan until Saturday is to carry out an additional search in some of the 64 compartments where people are expected to be found, as well as in 47 public areas such as bathrooms and shops. Divers also plan to expand the search to the cargo compartments.

The 6,825-ton Sewol was carrying 476 people when it capsized and sank off the southwestern island of Jindo on April 16. No bodies have been recovered since early Wednesday, leaving the death toll at 269. 

The Coast Guard revised upward the number of those missing to

35 on Wednesday, saying two Chinese nationals had been added to the list. It was later revealed, however, that the bodies of those Chinese nationals were recovered and buried.

 Officials said they have installed five layers of nets around the submerged vessel in order to prevent bodies from being swept away. Vessels and aircraft were also mobilized to scour waters up to 68 kilometers away from the site of the sinking.

Meanwhile, a member of the Coast Guard's air corps who suffered a stroke after taking part in search operations on Wednesday has regained consciousness following surgery, hospital officials said. (Yonhap)