The finder seems to work good while the boat is still, but when i start moving I get crazy readings, like 1100 feet in a river. It also does not seems to show the bottom but just a lot of interferance. It also seems to be reading a higher than normal speed, like 55 mph on my 17 foot Seahunt center console, my regular speedometer is not working to conpare it to. When I stop or slow way down the depth is correct again. I had this same problem with a Lowrance finder I had on this boat. Could it be electrical interferance or would the transducer be mounted wrong??