went to cabelas and purchased a 596c HD DI today. should be a big difference from the basic 550 grey scale. now I know i'm beating a dead horse here but I want the final word on this. I want to use this as a shoot thru hull ducer as I have it now, when I asked the pro's at cabelas (yea right...lol) about using a shoot thru he said yea it willwork but the picture will not get as crisp as if you where to use it at the transom ...true? if not I want to exchange it thru hummingbird for the latest and greatest shoot thru puck. sorry for killing this topic.