>> sure. >> recap that for us for folks just tuning in. >> you have an underwater mountain like the zenith plateau south of the area they're looking at. the scale is distorted because this is a couple of miles of ocean water >> a couple of miles. >> yeah. this is a tiny ship way up there and this is a tiny vehicle hanging down by a long cable. this is also much bigger than it really is. this would be a tiny spec on this type of topography. so what we're looking at is the sound emanating from here. most people think the sound would come directly to the listening device but that's not true. this sound is bouncing off topography like this and getting bent around by ocean currents and ocean thermal structures so it's got all different paths that the ocean is taking that sound. >> many say the ocean does play tricks with sound. i think this gives us an idea. it occurred to me those currents change. so from one day to the next you're not going to have a consistent --