21 is very, very crucial. i was wondering why they didn t launch the bluefin 21 right away. it s a matter of narrowing down the search area. they said, again, without a piece of wreckage confirmed, putting the pinger locater in the water was a risk. some people called it a waste of time, a waste of resources. it looks now like that may not be the case. but you really in most cases, according to the manufacturer, you do need a point where you can start. you need some kind of a piece of wreckage, something indicating that you re near the area where the plane went down before you should use these resources. they didn t have that this time, but they got fortunate maybe, maybe. brian todd, many thanks. i want to bring in thomas altshuler, the vice president of teledyne marine systems, the manufacturer of the equipment