us where air pockets can be found. >> when they're in a small compartment like this with an air bubble, they have to stay calm and breathe shallow and conserve the oxygen in that space. >> reporter: aside from the danger and difficulty, she says there's also a danger in trying to pump air into the overturned vessel. >> if you drill a hole in that ship in a compartment that has air in it, you risk letting the air out and allowing the ship to start to sink even more. that risks those survivors that might be in that space. >> reporter: but she says south korean rescue teams are very capable with advanced equipment and the best training. she says they'll need every ounce of that now. brian todd, cnn, washington. and now to the latest on the search for the missing malaysian