technology that people have talked about. one are man submersibles. i would highly advise against that. it takes a lot of equipment for something that doesn't give you much bottom time and then you have towed sleds. there are pluses and minuses with those, too. i think if they are going to do it, they need to start doing it now because it is going to take weeks to get the equipment out there and to the search area. >> i want to ask you about the bluefin-21 because we've been questioning all week whether or not this is the right device. it's the one they have and that's great. you mentioned others that are able to go deeper. it's exceeded its depth limit with some of these dives and people say there may be some residual risk to the vehicle because it is doing that. what does that mean? would it make the bluefin-21 inoperable? >> that depends. the pressure is building on you the whole time. you hear your ears pop when you dive into a swimming pool.