flight. >> reporter: the remus 6000 can navigate in waters almost 5,000 deeper than the bluefin 21, which is currently being used in the search for malaysia flight 370. after the remus auvs use side scan sonar to map the ocean floor, they usually come back with what is called low frequency images. these are pictures it took of the submerged plane in massachusetts. >> and this shows up as different from the surrounding area, indicating that there is something on the bottom for us to go look at. >> reporter: but take a look at these images taken at a higher frequency. >> you can clearly see the body of the plane, the two wings. >> reporter: so why isn't the remus 6000 in the indian ocean right now in the navy tells cnn that when searchers asked the u.s. government for an auv, the bluefin-21 was the only deep water vehicle it had available,