I have a x-87 with the transducer mounted on the trolling motor.Every time I lift the trolling motor up the unit stops reading the bottom.I have to turn the unit off - on. I have the sens level at 50% in shallow water.This drives me crazy....I called Lowrance and this was there responce.....When operating a sounder with the transducer out of the water it will begin to search for a bottom. This search feature is automatic. When the transducer is removed form the water it receives no echoes and the unit in auto-search can go through a wide range or depths to determine where the bottom is. When placed back in the water, particularly shallower depths such as less than 50 feet the sounder may determine a bottom to be surface clutter is it is currently searching up to 1000 feet. It will eventually come back to the actual depth but this can take some time depending on last known depth, water conditions, actual depth, and time out of the water for the transducer. <br />To reduce or eliminate this problem you may;<br />Turn the unit OFF before pulling the trolling motor transducer out of the water when changing spots. <br />operate the unit in CHART MANUAL MODE which disables the search function......THIS IS NOT WHAT I WANTED TO HEAR,I HAVE TO TURN THE UNIT OFF EVERY TIME I LIFT IT UP