bottles, things like this from merchant vessels. >> reporter: time is of theess sense to make that determination. here's another possibility in this rough part of ocean it's possible that search crews could miss floating objects because of the fallibility of the human eye and the possibility these objects are blending in with the water. historically visual searches have a 78% possibility for detection in a first search in flat, calm water. but when you is a lot of wave action that decreases. renee marsh, cnn washington. there are conflicts reports about the pilot of flight 307 and what if any role he played in the plane's disappearance. our jim clancy joins us now. the spotlight keeps coming back to the pilot. and yet there, is not one piece of evidence to suggest he is criminally intent in this.