Does anyone on here use a Garmin 220 or 320 while fishing? I am looking at buying another depth finder for my boat, primarily for finding structure and the depth of the water, but I would also like to be able to mark waypoints for structure. I have a garmin 320 that i used to use for hunting, and was thinking that instead of paying 700-1000 for a depth finder that did that, if I might could save some money and just use my handheld for that? Does anyone have any experience with something like that?