Any decent sonar will work, just make sure you're not using fish ID. I have a hard time fishing without it too, once you learn how to play with all your settings, and learn to read what fish are doing, hard water will be that much easier. I love mine, it's an older hummingbird, and I know what fish are doing on it, picking up chum cruising off to the side, chasing my bait or laying on bottom. I actually watched a laker last year rise 40 feet off bottom on my screen, looked down my hole in my hut and watched him come up and grab some chum I just threw down, realed up one of my rods and bam. Fish on.