Coast Guard officers search for missing crew members aboard the 129-ton Geumseong that sank off Jeju Island the previous day, in this photo provided by the Jeju Coast Guard, Nov. 9. Yonhap

The nighttime search operation to find 12 missing crew members from a fishing boat that sank the previous day continued for a second day Saturday, the coast guard said.

The authorities have mobilized 47 ships and five aircraft to conduct the nighttime search for the missing crew, according to the Jeju Coast Guard.

The 129-ton Geumseong was carrying 27 crew members — 16 Koreans and 11 Indonesians — when the Coast Guard received a distress call the previous day that the boat was sinking 24 kilometers off Jeju's Biyang Island.

Of the 27, 15 were rescued by a nearby vessel, including two who were found in a state of cardiac arrest and taken to nearby hospitals. The two, both Koreans, were later pronounced dead.

Aircraft will also be mobilized to drop 222 illumination flares to support the operation.

The Coast Guard, meanwhile, said the fishing boat is believed to be standing upright on the seafloor without having overturned. (Yonhap)

A Coast Guard vessel searches for missing crew members aboard the 129-ton Geumseong that sank off Jeju Island the previous day, in this photo provided by the Jeju Coast Guard, Nov. 9. Yonhap