learning, we are using an acoustic system. that means we send out a sound and it reflects off the sea floor and we listen to the reflection. by compositing successful reflections we create an image. we know these are rolling hills and that's the best news i have heard all week and the other thing is there is a lot of silt down there. >> why is that the best news you have heard all week? >> because the rolling hills -- you would be worse off if you were in canyons and valleys and if you have all sort of crevices and big boulders around. so rolling hills is not a bad place for a sonar. it is a matter of figure and ground. we want to see the figure from the ground. if it is just rolling hills and if the sediment is absorbing the sound to some extent things on top of it, reflective things like man made components of jets and metal objects should give us spectacular reflections which would allow us to see the difference between the man made