>> there was also a bat cabin called the observation chamber. a crew member. >> so. >> this is how you're sitting. this is how i'm sitting. and we could be there for hours. >> this is what's taking place. >> so we fire up the sonar system and it takes a sweep. if there is any solid stargts it will people and we will go ahead and look at it that way. >> by looking for wreckage, manned submersible offer an important dimension. >> you're saying that sometimes having a human being being able to look around, i could spot things that an unmanned