military coordination is not look in terms of the investigation itself. we'll leave that up to the investigation authorities. in terms of the search area that is being coordinated, we're looking in the area of most likely based on the evidence we have available to us for that search area. and likewise for the surface vessels and the submarine in the area that are looking for the ping. so it's credible evidence based on a combination of ocean modeling, drift, and all of the information that we have available to us. >> we're looking at about 20 original -- 20 search areas over the past several weeks, commander. are you feeling less optimistic? yesterday i was talking to the u.s. navy, and they said on the show, look, we haven't reacquired the signal. this is the most promising development we had, this possible ping. but they were losing optimism. are you? >> well, i think that earlier on, one of the australian authorities, the vice chief of defense force noted that it was like looking for a needle in a