South Korea ferry: The 'daunting task' of rescuing survivors

Poor conditionsand other obstacles meanrescue divers are facing the"daunting task" of rescuing passengers whomay have found air pockets insideaferry that sank off South Korea's southern coast.

But even if they have air to breathe, the threat of hypothermia is reducing their chances of survival.

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"Its a very difficult operation and while theremay be survivors, even if they're found, it'sgoing to be hazardous to bring them to the surface," said Kim Petersen, governor emeritus of the MaritimeSecurity Council and president and chairman of Security Dynamics.

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Twenty-five people, including a female crew member, at least five students and two teachers, were confirmed dead by South Korean coast guard officials Friday. But more than 270 passengers many of them high school students were missing and many are presumed dead.Officials put the number of survivors at 179.

The 146-metreSewolnow sits with just part of its keel visible in waters offMokpo, about 470 kilometresfrom Seoul. The interior of that shipis the focus of the desperate search for survivors.

Currently, there are 178 divers feeling their way around inside the vessel, diving in teams,running multiple safety lines, searching ina gridfashion as theylookfor openings that could lead tovoidswhere pockets of air could sustain life, Petersen said.

The working assumption, Petersen said, is that somepassengers were able to find air pockets in the vessel.But with divers planning to pump oxygen into the ship to help any survivors,the question is whether or not they're still alive.

Divers started pumping air into the submergedvesselearly on Friday. It is unclear whether the air is for a rescue or salvage operation.

Prof.GordonGiesbrecht, associate dean ofkinesiologyand recreations management at the University of Manitoba, said food shouldn't be anissue, as someone could live for weeks without it. Although the general rule is that people can only lastthree days without water, some survivors of disasters have shown they canlive longer,

Surviving hypothermia

This means passengers on the vessel would dieeither byasphyxiationor hypothermia, he said. Surviving hypothermia could depend on how extensivelythe passengers havebeen immersed in water.

With water temperatures ranging from 10 C to 12 C,Giesbrechtsaid it's unlikely that someone almost completely immersed in watercould survive past 24 hours.

"Peoplecould be in enclosed spaces with trapped air anywhere from full immersion up to theneck, to very little immersion. And in that case,people could survive for days."

However, with poor visibility and astrong current,divers are facing huge challenges finding surviving passengers.

"Its just a daunting task," Petersen said.

Any survivor whois found may be injured, suffering from hypothermia, and now have to be moved from a void deep inside the ship to the surface using scuba equipment they will most likely be unfamiliar with.

"The water is 10 C. Its murky, itsgoingto be pitch dark, it has to be the most frightening environment these desperate students could find themselves in, ifthereare any thats still alive," Petersen said.

"And then having to move through anenvironmentthatsgoingto have numerousobstacles, for example metal edges, broken glassandthen coupled with the current all of which makes for a daunting rescue scenario."

Petersen said it may take 15 to 20 minutes to follow the safety lines back through the maze of hallways and debris that would ultimately lead to the surface.

Rescue crew may also try to raise the vessel usinga crane to try toextract any survivors, but that might require more time than would be available, Petersen said.

Once a survivor has been found, Giesbrechtsaidtheres no rush to get them out, even if theyre suffering fromhypothermia.

"Whenyou'regoingto rescuesomebody, speed isnt the issue. If theyre stillalive, theyre in a very stablesituation so youcantakeyour time, knowing that in an hourtheirtemperature won't drop."

The rescuers should take the time to calm the passenger down, he said.

"Youve got the person, theyre alive.If ittook you an hour to get the person out of there, who cares."

"Basically youre going to teach somebody how to scuba dive in the worst possible conditions. Cold water, dark,survivalsituation. So you really have totake your time," Giesbrecht said.