and instead began using the so call bluefin 21. the submersible sonar system. he also said crews located an oil slick in the search area. they took samples and will be analyzing them in the coming days to figure out whether that oil has anything to do with flight 370. in the meantime, the two dozen ships and aircraft are scouring more than 47,000 square kilometers. so let's bring in our michael holmes who is live in perth with details on day 38 of the search. so michael, what can you tell us? apart from this news conference and of course these critical points here. we learn about this search going on underwater and we learned about this oil slick. >> reporter: yeah. a couple of headlines. more than two in this news conference by angus houston, the retired air chief marshal