this is not going to show up on some random fish-finder, you know, from some bertram going across fishing in the area. who has a receiver to hear these pings? >> well, agencies such as the navy, coast guard, et cetera, typically, can pick up on the signal, can either be done on the surface or by a towed array at a certain depth. >> how many receivers do you think are out there listening for a ping right now? is there any way to put a number on that? >> oh, gosh. >> ten, a dozen, a hundred? >> i can only speculate. i honestly don't know. >> okay. that's a fair answer because we don't know either. don, if it has to be an official boat, it would be great if we could put some kind of receiver on every little fishing vessel out there, not a ten-foot sciff. i get that but then we would be able to really cover some ground.