I moved to Selah, WA last fall and am now wanting to do some stillwater trout fishing primarily in the Cascade foothills (eastside). From what I have read here and other places it seems as if knowledge of the depth of the lakes and contour of the bottom are important. That brings my to a question I would like some input on from you guys and gals. I am considering the purchase of a depth finder for my recently purchased pontoon boat. I am looking at either the Smartcast by Hummingbird or a Fishin' Buddy from Cabela's. I do not plan to "search for fish," but to simply use the device to determine lake depth. I am leaning to the Smartcast because of its size and somewhat lower price, but I don't want to purchase it and then turn around and get the other because I made the wrong decision. What recomendations do you have for me? Is this even necessary or desirable or am I just wasting money that could be spent on another fly rod (you never have enough )?

Jim