I tried one a year ago, was not able to locate any fish with it. Did have about an 17" walleye so did a "hi-tech" experiment. Drilled a holes about 30', 60', & 90' from the unit, dropped him back down on a line about 10' below the ice in 23" of water in all three holes. Could see the fish in the 30 & 60, but despite any adjustments couldn't get any definite marks at 90. If I let him go to the bottom it was gone, even when I knew there was a fish in that immediate area I could not pick it up off the bottom. Long story short, it may have value locating suspended fish, if you are like me and looking for walleye or perch that stay close to the bottom, it wasn't of any value.