secondly, you have to have support teams for these. you need to have technicians, scientists, who know how to program them. how to read the data off of them. how to maintain them. how to even put them in and out of the water. this thing weighs about 1,700 pounds it's like lowering a small car into the water and retrieving it over and over again. it is difficult, and it is dangerous. and lastly, there is the issue of the terrain. we've talked about this many times, were ut we have this image they're going down to a flat ocean floor to map it, but that may not be the case as all. it could be much more like this, with hills and kreggs and valleys and these coulding going up and down and intersecting and doing all sorts of things that make it so much harder than it may appear. >> thanks so much, tom foreman. still to come in the "newsroom," the deadliest accident ever on mount everest jot got deadlier. details straight ahead. [ male announcer ] nearly 7 million clients.