surface. it has switches that start activating different deployments. there is dear in there packed in nicely. some of it floats to the surface there is a radio antenna that talks to the aircraft. and then the microphone, hydr are ophone is lit stening to a signal. they sent a cargo plane to indiana in recent days to deploy a cargo plane. >> anti-submarine mwarfare this is one of the tools that the navy has to look for and track the submarine. they need to find them and track them. >> on this mission, the buoys have been modified to detect sound in the range of black box