they've located it, but i have to see more data. >> we welcome our viewers who are joining us from around the world as we now simulcast on cnn's international network. we're talking with simon boxwell who is an oceanographer with the national oceanography center. the question is, if not a pinger from a black box, simon, what else could send up this pulse signal, that according to the chinese state news agency xinhua a chinese patrol ship has detected in the south indian ocean? >> well, a lot of equipment we deploy in the oceans, scientists want to find a ping. we know one uses pingers to transmit sound data, so we can focus in on our equipment. there are, as we heard, a lot of shims all using acoustic