I have a Lowrance X510c Fishfinder with a 200kHz Skimmer transom mount transducer. Just bought it in the Spring of 2010..it worked great for the first month......than i started to lose bottom/unit froze at times . It didn't matter if i was running 18 mph or stationary...today it kinda went crazy on me. blank screen...no bottom...and at the dock the bottom depth went from 2 feet to 12 feet and everywhere it between.Bottom returned after some time.Last week i had the boat out of the water and checked the transducers' installation...everything looked great..even cleaned the transducer. Today i checked the wiring/connections and transducer cable extension..looked okay..everything is new.Taking it back to the dealer here in town is not an option... i would be lucky to hear back from them next summer.Was thinking on ordering an Airman P66 transducer and trying it to see if the original transducer was the problem. Other than that i not sure what to do....any suggestions would help. Thanks Tug