the water. that's where you'll find the black boxes. that's where the pingers would be if they activated. so you shouldn't have to look very far. i really think that if these things had been working they would have been detected. so i suspect as in the case of air france 447 where also the pingers didn't work we probably need to conclude that they're not working, we just have to look by side scan sonar to find the debris. >> paul, a followup to you because you said there are two potential signals investigators could be working from, the pingers from the plaque boxblack boxes but also the transponder signal activated upon impact. so theoretically wouldn't that be helping searchers having more to go by? >> well actually the emergency locater transmitter needs to be above the water. so i think we can discount their signals right now. no we're looking for the pingers and hopefully the batteries will not exhaust by