see. in the indian ocean they are doing pre-planned missions because the vehicle doesn't come back for a long period of time. they have to use their best estimate to generate this. >> the side scan sonar looks weird. explain how this works. >> this is side scan sonar imamry. it travels through the water, hits the sea floor and continues on. that generates an image of what's on the sea floor. >> anderson, it's interesting because the closer they get the better the image but the higher up the more they can see what is beneath them. so it can be tedious to get a better idea of what is down there. >> are they getting realtime images or data -- i thought it was data they look at later. the fact there is silt down there could that make it harder to identify? >> well, the first one i think that is a james question. >> no, they are not getting realtime images.