air france 447 was on an underwater mountain range. if you go over just on the other side where this new search is taking place, the water can get rapidly down to about two and a half miles, and both of those require very different kinds of technology and approaches. david, help us understand on sort of the most basic level how you actually search an ocean. are you just looking for stuff? what sort of technology is deployed? how does this actually work? well, you know, it s time for the big whiteboard and some nice new sharpie. i really believe that. there s so much confusion and contradictory evidence. there were no witnesses. the last known position, the lkp, and we had a good idea where that was. and then we had four minutes of the maintenance burst that has