WATER HEIGHT ? — Looking at using an ultrasonic system (WINGONEER DC 5V Waterproof Ultrasonic Distance Sensor system ) and mounting the sensor on a post overlooking the river. I will use the waterproof sensor. Take the echo return time signal and use it to start and stop a counter. (Digiten 4 digit LED counter panel meter. ) Looking at the LTC6900 to create about a 5.6 KC time base for measuring the distance in feet. — A couple questions: Can I extend the cable between the control module and the sensor to 250 feet? If so can I use multi conductor cable, or would the sensor need to have coax? What kind of stability is reasonable to expect using these parts and overall method? Any thoughts and/or other ideas? How about a better way? Comments ? – Thanks