New crappie fisherman here. I have always fished the spawn and usually hang it up. Looking for a fish finder to show depth, water temp, and possibly structure. I'd like to continue fishing for them during the summer and I know a fish finder is key. The places I usually fish are shallow, 5-20ft tops. I have a 15 john boat that I will be putting it on. It's a stick steer so I'm assuming I need to attach it to the trolling motor. My budget is around $300. Any advice is greatly appreciated.