is the various moments when over the four-pinger locations that are being detected. the first and second were on saturday. the third and the fourth were on tuesday. now, we can only see on this map where they lost the first and the second, and that is also because the time distance was greater, one was two hours, 20, the other was 13. by the time you get to number three and number four you're really talking about a matter of minutes, 532 and seven minutes. >> these are detections being made by this device, which is being towed -- how many -- how far behind the ship? >> could be as far as five miles behind the ship. so when you look at this, i'm not real clear on this, it does say towed pinger locations, is that the location of the ship? >> we believe it is the location of the towed pinger. >> and moving up walking speed is what he said. >> one kilometer. >> so the fact that it is so