descended to try to intentionally get a cell phone tower signal because something was wrong. that's one of the possibilities that comes up again, you know, in that scenario. you can think of nefarious scenarios too. we don't have any more information once again from the malaysian authorities. >> rob, do you think it was a good idea to shift so much to the underwater search? i know there's still planes looking. they found an oil slick which may or may not be anything. what do you think about the wisdom of using the bluefin at this stage like this? >> i think it was timely to move into the underwater phase. it's clear the pingers are at the very edge of their life. so it was time to put sonar in the water. today highlighted that we do have all our eggs in one basket. you know, we have one vehicle, one auv operating at the very edge of its depth range.