my first problem is lack of ability to show fish within 20 feet the bottom in depths greater than 80 to 100 feet. i usually have the depth range zoomed in within 10 to 20 feet ot the bottom. also i have a problem reading bottom quite often when using the 50 power. hardly ever a problem when using 200. the depth display just blinks showing an incorrect depth. usually after 1 to 10 minutes of blinking while sitting achored it will start to read properly but only if boat is not moving. it does this even when all other electrical equipment is turned off including radio, motor, and baitwell. any advice or input would be greatly appreciated.